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On April 21, 2024, 11:35 AM

Exercise 7.6 - Chapter 7 Integrals class 12 ncert solutions Maths - SaraNextGen [2024-2025]


Question 1:

x sin x

Answer:

Let I = https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7675/NCERT_Solution_Math_Chapter_7_final_html_16f819ca.gif

Taking x as first function and sin x as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7675/NCERT_Solution_Math_Chapter_7_final_html_m5b52456b.gif

Question 2:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7676/NCERT_Solution_Math_Chapter_7_final_html_m565b8df6.gif

Answer:

Let I = https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7676/NCERT_Solution_Math_Chapter_7_final_html_m242fdeeb.gif

Taking x as first function and sin 3x as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7676/NCERT_Solution_Math_Chapter_7_final_html_m214c7ae3.gif

Question 3:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7677/NCERT_Solution_Math_Chapter_7_final_html_45da2d8.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7677/NCERT_Solution_Math_Chapter_7_final_html_5ecce068.gif

Taking x2 as first function and ex as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7677/NCERT_Solution_Math_Chapter_7_final_html_m1406435d.gif

Again integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7677/NCERT_Solution_Math_Chapter_7_final_html_243d97bb.gif

Question 4:

x logx

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7678/NCERT_Solution_Math_Chapter_7_final_html_m78a8c8a4.gif

Taking log x as first function and x as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7678/NCERT_Solution_Math_Chapter_7_final_html_m5b95e34d.gif

Question 5:

x log 2x

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7679/NCERT_Solution_Math_Chapter_7_final_html_3c936f78.gif

Taking log 2x as first function and x as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7679/NCERT_Solution_Math_Chapter_7_final_html_m50a12fc3.gif

Question 6:

xlog x

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7680/NCERT_Solution_Math_Chapter_7_final_html_m50234465.gif

Taking log x as first function and x2 as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7680/NCERT_Solution_Math_Chapter_7_final_html_126181e4.gif

Question 7:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7681/NCERT_Solution_Math_Chapter_7_final_html_m70b6b8fb.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7681/NCERT_Solution_Math_Chapter_7_final_html_m7753b72d.gif

Taking https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7681/NCERT_Solution_Math_Chapter_7_final_html_m17c7f48.gif as first function and x as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7681/NCERT_Solution_Math_Chapter_7_final_html_m3a459646.gif

Question 8:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7682/NCERT_Solution_Math_Chapter_7_final_html_11d5bd80.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7682/NCERT_Solution_Math_Chapter_7_final_html_m475935f3.gif

Taking https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7682/NCERT_Solution_Math_Chapter_7_final_html_m1a8b5181.gif  as first function and x as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7682/NCERT_Solution_Math_Chapter_7_final_html_m19e79690.gif

Question 9:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7683/NCERT_Solution_Math_Chapter_7_final_html_5ad5a2f.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7683/NCERT_Solution_Math_Chapter_7_final_html_7b3b2f71.gif

Taking cos−1 x as first function and x as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7683/NCERT_Solution_Math_Chapter_7_final_html_1991c6d7.gif

Question 10:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7684/NCERT_Solution_Math_Chapter_7_final_html_2aa59a77.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7684/NCERT_Solution_Math_Chapter_7_final_html_37a9f912.gif

Taking https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7684/NCERT_Solution_Math_Chapter_7_final_html_2aa59a77.gif  as first function and 1 as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7684/NCERT_Solution_Math_Chapter_7_final_html_783e653d.gif

Question 11:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7686/NCERT_Solution_Math_Chapter_7_final_html_m7beafb64.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7686/NCERT_Solution_Math_Chapter_7_final_html_c428cc9.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7686/NCERT_Solution_Math_Chapter_7_final_html_m54c945f9.gif

Taking https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7686/NCERT_Solution_Math_Chapter_7_final_html_m47731349.gif  as first function and https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7686/NCERT_Solution_Math_Chapter_7_final_html_m5f93d4cd.gif  as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7686/NCERT_Solution_Math_Chapter_7_final_html_56d7e816.gif

Question 12:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7687/NCERT_Solution_Math_Chapter_7_final_html_4e99fa3a.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7687/NCERT_Solution_Math_Chapter_7_final_html_5977bb13.gif

Taking x as first function and sec2x as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7687/NCERT_Solution_Math_Chapter_7_final_html_m384594e7.gif

Question 13:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7688/NCERT_Solution_Math_Chapter_7_final_html_m1a8b5181.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7688/NCERT_Solution_Math_Chapter_7_final_html_226da9cf.gif

Taking https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7688/NCERT_Solution_Math_Chapter_7_final_html_m1a8b5181.gif  as first function and 1 as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7688/NCERT_Solution_Math_Chapter_7_final_html_m4bf69e04.gif

Question 14:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7689/NCERT_Solution_Math_Chapter_7_final_html_541373dc.gif

Answer:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7689/NCERT_Solution_Math_Chapter_7_final_html_m783b9696.gif

Taking https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7689/NCERT_Solution_Math_Chapter_7_final_html_m4b6918a2.gif  as first function and x as second function and integrating by parts, we obtain

I=log x 2∫xdx-∫ddxlog x 2∫xdxdx=x22log x 2-∫2log x .1x.x22dx=x22log x 2-∫xlog x dx

Again integrating by parts, we obtain

I = x22logx 2-log x ∫x dx-∫ddxlog x ∫x dxdx=x22logx 2-x22log x -∫1x.x22dx=x22logx 2-x22log x +12∫x dx=x22logx 2-x22log x +x24+C

Question 15:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_m7e288453.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_m7d7d9059.gif

Let I = I1 + I2 … (1)

Where, https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_5adba482.gif and https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_m3afbd7eb.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_508ac40a.gif

Taking log x as first function and xas second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_64161ae9.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_m3afbd7eb.gif

Taking log x as first function and 1 as second function and integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_m33301466.gif

Using equations (2) and (3) in (1), we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7691/NCERT_Solution_Math_Chapter_7_final_html_32c47506.gif

Question 16:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7695/NCERT_Solution_Math_Chapter_7_final_html_m16dbffa1.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7695/NCERT_Solution_Math_Chapter_7_final_html_m3fc69b14.gif

Lethttps://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7695/NCERT_Solution_Math_Chapter_7_final_html_8ec6dc1.gif

⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7695/NCERT_Solution_Math_Chapter_7_final_html_2d6339dd.gif

∴ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7695/NCERT_Solution_Math_Chapter_7_final_html_264157a1.gif

It is known that, https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7695/NCERT_Solution_Math_Chapter_7_final_html_20bec91b.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7695/NCERT_Solution_Math_Chapter_7_final_html_ma0bf94e.gif

Question 17:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7697/NCERT_Solution_Math_Chapter_7_final_html_41e8a549.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7697/NCERT_Solution_Math_Chapter_7_final_html_f2746bb.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7697/NCERT_Solution_Math_Chapter_7_final_html_356f9e57.gif

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7697/NCERT_Solution_Math_Chapter_7_final_html_4bcecbea.gif  ⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7697/NCERT_Solution_Math_Chapter_7_final_html_m311bf58a.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7697/NCERT_Solution_Math_Chapter_7_final_html_m692fc956.gif

It is known that, https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7697/NCERT_Solution_Math_Chapter_7_final_html_20bec91b.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7697/NCERT_Solution_Math_Chapter_7_final_html_m234a6149.gif

Question 18:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7699/NCERT_Solution_Math_Chapter_7_final_html_2d60c21c.gif

Answer:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7699/NCERT_Solution_Math_Chapter_7_final_html_1b8fb60a.gif

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7699/NCERT_Solution_Math_Chapter_7_final_html_23c6706d.gif  ⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7699/NCERT_Solution_Math_Chapter_7_final_html_23e4f06.gif

It is known that, https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7699/NCERT_Solution_Math_Chapter_7_final_html_20bec91b.gif

From equation (1), we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7699/NCERT_Solution_Math_Chapter_7_final_html_m483f6657.gif

Question 19:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7702/NCERT_Solution_Math_Chapter_7_final_html_425f49ab.gif

Answer:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7702/NCERT_Solution_Math_Chapter_7_final_html_509a61e0.gif

Also, let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7702/NCERT_Solution_Math_Chapter_7_final_html_m47d9edac.gif  ⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7702/NCERT_Solution_Math_Chapter_7_final_html_m123a8371.gif

It is known that, https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7702/NCERT_Solution_Math_Chapter_7_final_html_20bec91b.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7702/NCERT_Solution_Math_Chapter_7_final_html_m7a0cc9fc.gif

Question 20:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7705/NCERT_Solution_Math_Chapter_7_final_html_m5d04b491.gif

Answer:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7705/NCERT_Solution_Math_Chapter_7_final_html_m1ffb9b2d.gif

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7705/NCERT_Solution_Math_Chapter_7_final_html_2cc6670b.gif  ⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7705/NCERT_Solution_Math_Chapter_7_final_html_m4e016495.gif

It is known that, https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7705/NCERT_Solution_Math_Chapter_7_final_html_20bec91b.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7705/NCERT_Solution_Math_Chapter_7_final_html_m3379bca.gif

Question 21:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7707/NCERT_Solution_Math_Chapter_7_final_html_m198871a2.gif

Answer:

Lethttps://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7707/NCERT_Solution_Math_Chapter_7_final_html_m349755a1.gif

Integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7707/NCERT_Solution_Math_Chapter_7_final_html_m72845c80.gif

Again integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7707/NCERT_Solution_Math_Chapter_7_final_html_m624ee5cc.gif

Question 22:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7710/NCERT_Solution_Math_Chapter_7_final_html_5c4b1fa6.gif

Answer:

Lethttps://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7710/NCERT_Solution_Math_Chapter_7_final_html_2effc955.gif  ⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7710/NCERT_Solution_Math_Chapter_7_final_html_m5b0e6d85.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7710/NCERT_Solution_Math_Chapter_7_final_html_2c176593.gif  = 2θ

⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7710/NCERT_Solution_Math_Chapter_7_final_html_1772d35e.gif https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7710/NCERT_Solution_Math_Chapter_7_final_html_m2a375b8f.gif

Integrating by parts, we obtain

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7710/NCERT_Solution_Math_Chapter_7_final_html_m2f12cf1c.gif

Question 23:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7712/NCERT_Solution_Math_Chapter_7_final_html_36e73ee8.gif  equals

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7712/NCERT_Solution_Math_Chapter_7_final_html_m2073483f.gif

Answer:

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7712/NCERT_Solution_Math_Chapter_7_final_html_56dd90a3.gif

Also, let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7712/NCERT_Solution_Math_Chapter_7_final_html_770f1019.gif  ⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7712/NCERT_Solution_Math_Chapter_7_final_html_27cd530.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7712/NCERT_Solution_Math_Chapter_7_final_html_m3e91749d.gif

Hence, the correct Answer is A.

Question 24:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7714/NCERT_Solution_Math_Chapter_7_final_html_46f2088a.gif  equals

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7714/NCERT_Solution_Math_Chapter_7_final_html_42378067.gif

Answer:

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7714/NCERT_Solution_Math_Chapter_7_final_html_46f2088a.gif

Let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7714/NCERT_Solution_Math_Chapter_7_final_html_594a5f7.gif

Also, let https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7714/NCERT_Solution_Math_Chapter_7_final_html_m1536fdf4.gif  ⇒ https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7714/NCERT_Solution_Math_Chapter_7_final_html_m7b826a5e.gif

It is known that, https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7714/NCERT_Solution_Math_Chapter_7_final_html_20bec91b.gif

https://img-nm.mnimgs.com/img/study_content/curr/1/12/15/236/7714/NCERT_Solution_Math_Chapter_7_final_html_31dddd75.gif

Hence, the correct Answer is B.

Also Read : Exercise-7.7-Chapter-7-Integrals-class-12-ncert-solutions-Maths

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