Thread: Trig Equation & Expression

hi guys im having a bit of trouble with this 2 questions from my text book.

1. Find the exact value of the expression:

cos(arctan3/4)+tan(arccos3/5)

2. Solve the trig Eq:

2cos^3(x)+5cos^2(x)=2-cos(x)

can you guy please post a worked solution if you can im out of ideas.

thanks

For the first 1 draw the triangle(to understand) and then use your calculator

and for the second
2cos^3(x)+5cos^2(x)=2-cos(x)

--> 2cos^3(x)+5cos^2(x)+cos(x)-2=0

factorize and then solve for x...

Going to need more help then that

Show me what you have tried to do or what you don't understand and then we can take it from there....