# Math Help - I need help with trig

1. ## I need help with trig

IV BEEN WORKING ON THESE QUESTIONS FOR A VERY LONG TIME AND I CANT GET THE ANSWERS.

A) CALCULATE SIN225+COS120-TAN(-330)

B) (COS30)(COS30)=(SIN30)(SIN30)

I DONT KNOW HOW BUT LEFT HAS TO BE EQUAL TO RIGHT FOR PART B

2. Hello, Viviana!

A) Calculate: . $\sin225^o+\cos120^o-\tan(\text{-}330^o)$
You're expected to know the trig values of "standard angles."

. . $\begin{array}{ccccc}\sin225^o &=&\text{-}\sin45^o &=& \text{-}\frac{\sqrt{2}}{2}\\ \\[-4mm]

\cos 120^o &=&\text{-}\cos60^o &=&\text{-}\frac{1}{2} \\ \\[-4mm]

\tan (\text{-}330^o) &=&\tan30^o &=&\frac{\sqrt{3}}{3} \end{array} \quad\hdots\;\text{ etc.}$

$B)\;\;(\cos30^o)(\cos30^o) \:=\:(\sin30^o)(\sin30^o)$ . ??

I DONT KNOW HOW BUT LEFT HAS TO BE EQUAL TO RIGHT FOR PART B
That is quite impossible . . . equivalent to: $3 = 1$

AND TAKE OFF YOUR CAPS-LOCK.

. . IT'S IMPOLITE TO SHOUT.