Question

Is it right to say cos(60+ 30) = cos 60 cos30 − sin 60 sin 30​

Answer 1

Answer:

Rate of interest is 33.33 %

Step-by-step explanation:

Given,

Principal , p = 1200

Time , t = 6 years

Simple interest = 2400

Rate, r = ?

We know that,

SI = \frac{p \times r\times t}{100}SI=

100

p×r×t

2400 = \frac{1200 \times r \times 6}{100}2400=

100

1200×r×6

r = \frac{100\times 2400}{1200\times 6}r=

1200×6

100×2400

r = \frac{100}{3}r=

3

100

r = 33.333 %

Rate of interest

Answer 2

Answer:

yes

Step-by-step explanation:

yes it is absolutely right as

Cos(a+b)= cos a cos b - sin a sin b