Double Angle Formula

Question 1

Using double angles:

2sinθcosθ = ?

Answer 1

= sin(2θ)

Question 2

Using double angles:

sin(2θ) = ?

Answer 2

= 2sinθcosθ

Question 3

Using double angles:

cos(2θ) = ?

Answer 3

= cos²θ- sin²θ

= 2cos²θ-1

= 1- sin²θ

Question 4

Using double angles:

1-2sin²θ = ?

Answer 4

=cos(2θ)

Question 5

Using double angles:

2cos²θ-1 = ?

Answer 5

= cos(2θ)

Question 6

Using double angles:

cos²θ-sin²θ = ?

Answer 6

= cos(2θ)

Question 7

Using double angles:

Answer 7

= tan(2θ)

Question 8

Using double angles:

tan(2θ) = ?

Answer 8