Question

Evaluate: ${\int }_0^{\frac{\pi }{2}}\left(\text{7 sin t - 2 cos t}\right)dt$

• A. 5
• B. 2
• C. 7
• D. \N

Answer 1

The correct option is A 5

${\int }_0^{\frac{\pi }{2}}(7sint-2cost)dt=(-7cost-2sint){|}_0^{\frac{\pi }{2}}$
$=(-2-(-7\left)\right)=5$