Pre calc help! I did some questions but I don’t understand how to do the others!! :(
tan ( arccos (2/3) )
We are looking for the tangent of an angle whose cosine is 2/3
So..we know x / r and we are looking for y/ x...so we have
sqrt ( 3^2 - 2^2) = sqrt 5 = y
So....y / x = sqrt(5) / 2
cos ( arcsin (-3/5) )
We are looking for the cosine .... (x / r)..... of an angle whose sin is -3/5 = y / r
So we need to find x
sqrt [ 5^2 - (-3)^2 ] = sqrt [ 25 - 9 ] = 4 = x
This angle is in the 4th quadrant....the cosine is positive here
So...this evaluates to x / r = 4/5
sec (arcos (x) )
The cosine of this angle = x / 1
So..the sec is the reciprocal, 1 / x
cot ( arccos (3x) )
The cosine of this angle = [3x] / 1 = 3x
We are looking for the cot = cos / sine
So...the sine =
sqrt [ 1 - [3x]^2 ] = sqrt [ 1 - 9x^2 ]
And the cotangent is
[ 3x] / sqrt [ 1 - 9x^2 ]