Evaluate: $sin 25^{o} cos 65^{o} + cos 25^{o} sin 65^{o}$ .

Open in App

Solution

$sin 25^{o} cos 65^{o} + cos 25^{o} sin 65^{o} = sin 25 cos (90 - 25) + cos 25 sin (90 - 25)$
$= sin 25 sin 25 + cos 25 cos 25$
$= {sin}^{2} 25 + {cos}^{2} 25$
$= 1$ $[{sin}^{2} A + {cos}^{2} B = 1]$

Suggest Corrections

Similar questions

1)

\frac{s i n^{2} 63^{o} + s i n^{2} 27^{o}}{c o s^{2} 17^{o} + c o s^{2} 73^{o}}

2)

s i n 25^{o} c o s 65^{o} + c o s 25^{o} s i n 65^{o}

Evaluate : $\int \frac{x^{3}}{(x - 1) (x^{2} + 1)} d x .$

Evaluate $\int \frac{s i n x - x c o s x}{x (x + s i n x)}$ dx.

Evaluate : $\int_{0}^{π} \frac{x t a n x}{s e c x + t a n x} d x .$ OR Evaluate : $\int_{1}^{4} {|x-1|+|x-2|+|x-4|}dx.$

Evaluate: $\int_{0}^{\frac{π}{2}} \frac{s i n^{2} x}{s i n x + c o s x} d x .$

Evaluate: $\int_{- 1}^{2} (e^{3 x} + 7 x - 5) d x$ as a limit of sums.

Join BYJU'S Learning Program