Question

cos47*cos43-sin47*sin43=?​

Answer 1

Answer:

$cos47 \times cos43 - sin47 \times sin43 \\ = cos47 \times sin47 - \sin47 \times \cos47 \\ = \cos(47) \times \frac{1}{ \cos(47) } - \sin(47) \times \frac{1}{ \sin(47) } \\ = 1 - 1 \\ = 0$

Answer 2

Answer:⇒ sin43°cos(90 - 43)° + cos43°sin(90 - 43)°

⇒ sin43°sin43° + cos43°cos43°

⇒ sin243° + cos243°

= 1

[Since, sin2θ + cos2θ = 1]

Step-by-step explanation: