logo

Ask Questions, Get Answers

 
X
 Search
Want to ask us a question? Click here
Browse Questions
Ad
Home  >>  JEEMAIN and AIPMT  >>  Mathematics  >>  Class12  >>  Integral Calculus
0 votes

Integrate : $\cos ^3 x dx$

$(a)\;\frac{-3}{4} \sin x +\frac{1}{12} \sin 3x +c \\(b)\;\frac{3}{4} \sin x +\frac{1}{12} \sin 3x +c \\(c)\;\frac{3}{4} \cos +\frac{1}{12} \cos 3x+c \\ (d)\;None$

Can you answer this question?
 
 

1 Answer

0 votes
Use trigonometry property:-
$\cos^3 x= \large\frac{3 \cos x + \cos 3x}{4}$
=> $\large\frac{1}{4}$$\int 3 \cos x +\cos 3x dx$
$\large\frac{3}{4} $$\sin x +\large\frac{1}{12}$$ \sin 3x +c$
Hence b is the correct answer.
answered Jan 3, 2014 by meena.p
 
Ask Question
student study plans
x
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App
...