Question

2cosA-4sinA how to convert it into cos(A+B) form ??​

Answer 1

Answer:

(1/4) [ cos (A+26.56) ]

Step-by-step explanation:

• 2 cosA + 4 sinA

divide the equation by 4

• (1/4) [ (1/2) cosA + sinA]-------------------------eq.1

Cos(A+B) = cosA.cosB - sinA.sinB------------------eq.2

We have to bring eq.1 in forms of eq.2

By comparison,

cosB = 1/2 and sinB = -1

which gives ∆B = 26.56°

so it can be written as

• (1/4) [ cos (A + 26.56) ]