# If Sin(θ)=3/5

• Jul 8th 2012, 12:24 PM
MathRaven
If Sin(θ)=3/5
Spending my summer studying on my own, and I have come across some things which I would like to see how they are solved.
If you are capable of completing, please show work instead of just answers so that I can follow what you did, and take notes on it.

If sin(θ) = 3/5 and θ is in Quad II, determine in EXACT form the following

a) sin(θ + π/6)

b) cos(5π/3 - θ)

c) cos(20)

d) csc(π/2 - θ)
• Jul 8th 2012, 12:41 PM
Plato
Re: If Sin(θ)=3/5
Quote:

Originally Posted by MathRaven
Spending my summer studying on my own, and I have come across some things which I would like to see how they are solved.
If you are capable of completing, please show work instead of just answers so that I can follow what you did, and take notes on it.
If sin(θ) = 3/5 and θ is in Quad II, determine in EXACT form the following
a) sin(θ + π/6)
b) cos(5π/3 - θ)
c) cos(20)
d) csc(π/2 - θ)

For part a) you need
$\displaystyle \sin(A+B)=\sin(A)\cos(B)+\sin(B)\cos(A)$ and $\displaystyle \cos(\theta)=\frac{-4}{5}$.

Now you do some.
• Jul 8th 2012, 02:36 PM
Deveno
Re: If Sin(θ)=3/5
for part b) you need to know that:

$\displaystyle \cos(A + B) = \cos(A)\cos(B) - \sin(A)\sin(B)$