Let Θ be an acute angle such that sin Θ = 0.28. Find the value of cos Θ using trig identities. Round your answer to two decimal places.?

sin²θ + cos²θ = 1
(0.28)² + cos²θ = 1
cos²θ = 1 - (0.28)²
cos²θ = 0.9216
cosθ = 0.96, for acute angle θ

Hence, cosθ = 0.96

Use a Pythagorean Trigonometric identity such as the one shown below,
which is derived from using the pythagorean theorem to a right triangle inscribed in the "Unit Circle" with a radius of 1.

[sin(Θ)]^2 + [cos(Θ)]^2 = 1
Simply rearrange for cos(Θ). There is a subtraction and a division that must be performed.

cos(Θ) = √[1 - ((sin(Θ))^2]
Then you substitute the known value of sine theta.


cos(Θ) = √[1 - (0.28)^2]

And yeah, you can compute it.

cos Θ = √ ( 1 - 0.28²)...you compute