Write the integral as a sum of integrals without absolute values and evaluate.
int_(0)^(pi)|cos x|dx
1 Answers
Best Answer
Step 1
Given- int_(0)^(pi)|cos x|dx
To find- Evaluating the above integral using proper identities.
Concept used- As the given integral is in modulus, so break the limit as per the given function.
Step 2
Explanation- As the above integral in modulus, so using the property of modulus, proceeding as follows,
Let, I=int_(0)^(pi)|cos x|dx
Now, solving further,
Splitting the function from 0 to (pi)/(2) and (pi)/(2) to pi and we know that cos x is postive for 0 to (pi)/(2) and negtaive for (pi)/(2) to pi .
I=int_(0)^((pi)/(2))cos xdx-int_((pi)/(2))^(pi)cos x dx
=[sin x]_(0)^((pi)/(2))-[sin x]_((pi)/(2))^(pi)
=[sin (pi)/(2)-sin 0]-[sin pi -sin (pi)/(2)]
=1-0-0+1
=2
Answer- The value of the integral int_(0)^(pi)|cos x|dx is 2.