Question

Find the value of $\sin x$ if $0^{\circ }<x<{90}^{\circ }$ and $5{\sin }^{2}x=7\sin x-2$

• A. $1.00$
• B. $0.71$
• C. $0.40$
• D. $0.38$
• E. $0.35$

Answer 1

The correct option is C $0.40$

Given, $5{\sin }^{2}x=7\sin x-2$
$5{\sin }^{2}x-7\sin x+2=0$ , which gives

$\sin x=(7\pm \sqrt{9})/10=(7\pm 3)/10=1,0.4$
Since $0<x<90$ , the correct answer is $0.40$.