Question

Find the value of Sin (315°) + Cos (225°)❤​

Answer 1

Answer:

The answer is

$= - \sqrt{2}$

Explanation:

Here, we have to find out the value of

$\sin(315) + \cos(225)$

then,

$\sin(3 \times 90 + 45) + \cos(2 \times 90 + 45)$

$= - \cos(45) - \cos(45)$

$= - 2 \cos(45)$

$= - 2 \times \frac{1}{ \sqrt{2} }$

$= - \sqrt{2}$

Thanks a lot...

Answer 2

$\sin(315) + \cos(225)$

$\implies \sin(360° - 45°) + \cos(270° - 45°)$

We know that,

$\blue{\boxed{\sin(360°-\theta=-\sin(\theta)}}$

$\blue{\boxed{\cos(270°-\theta=-\cos(\theta)}}$

$\implies -\sin(45°) + [-\cos(45°)]$

$\implies -\frac{1}{\sqrt{2}} -\frac{1}{\sqrt{2}}$

$\implies \frac{-2}{\sqrt{2}}$

$\orange{\boxed{\therefore \sin (315°) + \cos (225°) =-\sqrt{2}}}$

HOPE THAT HELPS!!