Question 4: true?
question 5: true
Answer:
there is no diagram for the question so I don't know.
By dividing both numbers by 25, it will be 1/4
U = sec x ( substitution )
u² + 2 u = 0
u ( u + 2 ) = 0
u = 0, or u = - 2
1/cos x = 0 1/cos x = - 2
(not accepted ) cos x = -1/2
x 1 = 2π/3, x 2 = 4π/3