1
The integral 80 0 4 ( + 9 + 16 2 )d is equal to :
- 3 4
- 4 3
- 6 43
- 2 3
Answer
(2) 4 3
Solution
Put - = t ( + ) d = dt
t2 = 1 - 2 2 = 1 - t2
= 0 t = -1; = 4 t = 0
I = 80 -10 dt9 + 16(1 - t2) = 80 -10 dt25 - 16t2
= 80 12 5 4 [ | 5 + 4t5 - 4t | ]-10
= 2 ( 1 - 19 )
= 2 9 = 4 3
Answer: (2)
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