Answer:
what this is so confusing
Answer:
7
Step-by-step explanation:
So, substitute in your 4 for r, 2(3) + 1. Multiply 2 and 3 to get 6 and then add a to get 7. I hope this helps :)
Answer:

Step-by-step explanation:
Given

Required
Solve
Let

Differentiate



Make dx the subject

The given integral becomes:



Recall that: 
Make
the subject

Square both sides


Substitute
for
in 

Simplify



In standard integration

So, the expression becomes:


Recall that: 

Answer:
13/21
Step-by-step explanation: