Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.

Please verify your account before proceeding.

In this lesson, we will learn how to use a half-angle identity to find an exact value and simplify expressions.

Q1:

Using the half-angle formulas, find the exact value of s i n ( 1 5 ) ∘ .

Q2:

Using the half angle formulas, find the exact value of s i n 𝜋 8 .

Q3:

Using the half angle formulas, find the exact value of t a n ( 1 5 ) ∘ .

Q4:

Using the half-angle formulas, find the exact value of c o s ( 1 5 ) ∘ .

Q5:

Find the value of 6 4 4 0 8 0 3 0 0 1 6 0 c o s c o s c o s c o s ∘ ∘ ∘ ∘ without using a calculator.

Q6:

Find the value of s i n c o s s i n c o s 𝜋 1 6 𝜋 1 6 − 𝜋 1 6 𝜋 1 6 3 3 without using a calculator.

Q7:

Evaluate 1 6 1 5 7 3 0 ′ 1 5 7 3 0 ′ s i n c o s ∘ ∘ without using a calculator.

Q8:

Using the half angle formulas, find the exact value of c o s 𝜋 8 .

Q9:

Evaluate 8 1 0 5 1 0 5 s e c c s c ∘ ∘ without using a calculator.

Q10:

Evaluate 2 √ 3 1 5 − √ 3 c o s 2 ∘ without using a calculator.

Q11:

Evaluate 1 2 − 1 5 c o s 2 ∘ without using a calculator.

Don’t have an account? Sign Up