Question

find the value of cos θ if sin θ=1/2;0 degrees< θ< 90 degrees

Answer 1

Answer:

cosΘ = $\frac{\sqrt{3} }{2}$

Step-by-step explanation:

sin²Θ + cos²Θ = 1 ( subtract sin²Θ from both sides )

cos²Θ = 1 - sin²Θ ( take square root of both sides )

cosΘ = ± $\sqrt{1-sin^20}$

       = ± $\sqrt{1-(\frac{1}{2})^2 }$

       = ± $\sqrt{1-\frac{1}{4} }$

      = ± $\sqrt{\frac{3}{4} }$

     = ± $\frac{\sqrt{3} }{2}$

since 0° < Θ < 90° , then

cosΘ = $\frac{\sqrt{3} }{2}$