Question

(cos 0 + sin 30 + sin 45) (sin 90 + cos 60 - cos 45) = ?​

Answer 1

Answer:

(1+1/2+1√2)(1+1/2-1/√2)

(2+1+√2) (2+1-√2)

2 2

(3+√2) (3-√2)

2 2

using (a+b)(a-b)= a²-b²

(3/2)²-(√2/2)²

9/4-2/4

7/4