Prove that. 1-sin2A=2sin^2(45-A)
1 answer:
You might be interested in
Answer: We can arrange the steps with help of below explanation.
Step-by-step explanation:
Here ABC is a triangle,
Draw a perpendicular from BD to side AC ( construction)
where
In the right triangle BCD, from the definition of cosine:
cos C =CD/ BC
CD= a cos C
Subtracting this from the side b, we see that
DA= b-acos C
In the triangle BCD, from the definition of sine:
sin C =BD / a
BD = a sin C
In the triangle ADB, applying the Pythagorean Theorem
Substituting for BD and DA from (2) and (3)
⇒ ( On simplification)
⇒
⇒
⇒ (because,
)
