The minimum value of 4sin2 θ + 5cos2 θ is?
Answer & explanation
Correct answer: option 4
4sin2 θ + 5cos2 θ
⇒ 4sin2 θ + 4cos2 θ + cos2 θ
⇒ 4 + cos2 θ
since cos2 θ > 0 ; minimum value occurs when cos2 θ = 0
∴ minimum value = 4
The minimum value of 4sin2 θ + 5cos2 θ is?
Correct answer: option 4
4sin2 θ + 5cos2 θ
⇒ 4sin2 θ + 4cos2 θ + cos2 θ
⇒ 4 + cos2 θ
since cos2 θ > 0 ; minimum value occurs when cos2 θ = 0
∴ minimum value = 4