Question 1107462: if sin(x+30)°=cos40° find x
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! if you are allowed to use your calculator to find the answer to this poroblem, then:
cos(40) = .7660444431.
let the angle you are looking for the sine of be equal to y.
you get sin(y) = .7660444431.
arcsin(.766044431) = y
solve for y to get y = 50 degrees.
y is equal to x + 30 which makes x equal to 20 degrees.
you get sin(20 + 30) = cos(40)
simplify to get sin(50) = cos(40).
sin(50) = .7660444431.
cos(40) = the same.
x = 20 degrees is your solution.
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