If sin θ = 15 over 17, use the Pythagorean identity to find cos θ.
Solution:
It is given that
sin θ = 15/17
Using the trigonometric identities
sin θ = opposite/ hypotenuse
cos θ = adjacent/ hypotenuse
tan θ = opposite/ adjacent
Here hypotenuse = 17
Opposite = 15
Assume adjacent = x
Using the pythagorean identity
Hypotenuse2 = Opposite2 + Adjacent2
Substituting the values
172 = 152 + x2
It can be written as
x2 = 172 - 152
x = √289 - 225
x = √64
x = ±8
So we get
cos θ = ±8/17
Therefore, cos θ = ±8/17.
If sin θ = 15 over 17, use the Pythagorean identity to find cos θ.
Summary:
If sin θ = 15 over 17, using the pythagorean identity cos θ = ±8/17.
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