Question

Find the value of cos (-1710º).​

Answer 1

Answer:

0 is the answer

hope it is useful

Answer 2

$\star\:\:\:\bf\large\underline\blue{Question:-}$

• Find the value of $\cos1710 \degree$

$\star\:\:\:\bf\large\underline\blue{Solution:-}$

$\cos1710 \degree$

$= \cos(1710 \degree \times \frac{\pi}{180} )$

$= \cos( \frac{1710\pi}{180} )$

$= \cos( \frac{ \cancel{90} \times 19\pi}{ \cancel{90} \times 2} )$

$= \cos( \frac{19\pi}{2} )$

$= \cos( 9\frac{1}{2}\pi )$

$= \cos( 10\pi - \frac{\pi}{2})$

As value of of $\cos x$ repeats after an interval of $2\pi$,Hence we are ignoring $5\times 2\pi$ i.e., $10\pi$.

So,

$= \cos( 10\pi - \frac{\pi}{2})$

$= \cos( - \frac{\pi}{2} )$

Now, we know that,

$\cos( - x) = \cos( x )$

So,

$= \cos( - \frac{\pi}{2} )$

$= \cos( \frac{\pi}{2} )$

$= \cos90\degree$

$= 0$

$\star\:\:\:\bf\large\underline\blue{Answer:-}$

• $\cos(1710 \degree) = 0$