Question

2 cos 22 1/2 degree sin 22 1/2 degree evaluate
question 19 and 20) ii

Answer 1

2cos22.5°sin22.5°=sin2(22.5°)
=sin45°
=1/✓2

Answer 2

Answer:

$2\cos(22.5)\sin(22.5)=\frac{1}{\sqrt2}$

Step-by-step explanation:

Given : Expression $2\cos(22\frac{1}{2})\sin(22\frac{1}{2})$

To find : Evaluate the expression ?

Solution :

Expression $2\cos(22\frac{1}{2})\sin(22\frac{1}{2})$

$=2\cos(22.5)\sin(22.5)$

We know, $2\cos A\sin A=\sin 2A$

Applying in the expression,

$2\cos(22.5)\sin(22.5)=\sin(2\times 22.5)$

$2\cos(22.5)\sin(22.5)=\sin(45)$

$2\cos(22.5)\sin(22.5)=\frac{1}{\sqrt2}$

Therefore, $2\cos(22.5)\sin(22.5)=\frac{1}{\sqrt2}$