Option A
<em><u>Solution:</u></em>
Given that we have to rewrite with only sin x and cos x
Given is cos 3x
We know that,
Therefore,
---- eqn 1
We know that,
Substituting these values in eqn 1
-------- eqn 2
We know that,
Applying this in above eqn 2, we get
Therefore,
Option A is correct
Answer:
-3 is not a solution
Step-by-step explanation:
Subtstitute the possible solution into the equation and see if it is true
3x -5 = 4+2x
3(-3) -5 = 4+2(-3)
-9-5 = 4-6
-14 = -2
This is not true so -3 is not a solution