Practicing Success
If $\tan A=\frac{2}{3}$, then what is the value of the following? $\left(5 \sin ^2 A-2 \cos ^2 A\right) \div\left(15 \sin ^2 A+3 \cos ^2 A\right)$ |
$\frac{21}{47} $ $\frac{2}{87} $ $\frac{2}{5} $ $\frac{3}{77}$ |
$\frac{2}{87} $ |
$\left(5 \sin ^2 A-2 \cos ^2 A\right) \div\left(15 \sin ^2 A+3 \cos ^2 A\right)$ Dividing denominator and numerator by cos²A = $\frac{5\frac{sin^2A}{cos^2A}-2}{15\frac{sin^2A}{cos^2A}+3}$ = $\frac{5tan^2A - 2}{15tan^2A +3}$ Putting the value of tanA = $\frac{5.\frac{4}{9} - 2}{15.\frac{4}{9} + 3}$ = $\frac{\frac{2}{9}}{\frac{29}{3}}$ = $\frac{2}{87}$ |