Question

(sin^2a/2-cos^2a/2)/sina/2×cosa/2=1-sina/2​

Answer 1

sinA+cosA

+

sinA+cosA

sinA−cosA

=

(sinA−cosA)(sinA+cosA)

(sinA+cosA)

2

+

(sinA−cosA)(sinA+cosA)

(sinA−cosA)

2

=

sin

2

A−cos

2

A

sin

2

A+cos

2

A+2sinAcosA+sin

2

A+cos

2

A−2sinAcosA

=

sin

2

A−cos

2

A

2

=

sin

2

A−(1−sin

2

A)

2

=

2sin

2

A−1

2

=

2(1−cos

2

A)−1

2

=

1−2cos

2

A

2

Answer 2

Step-by-step explanation:

$tan15 = 2 - \sqrt{3}$