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The least value of 2sin^2theta+3cos^2the...

The least value of `2sin^2theta+3cos^2theta` is 1 (b) 2 (c) 3 (d) 5

A

1

B

2

C

3

D

5

Text Solution

Verified by Experts

The correct Answer is:
B
`sin^4theta+cos^4theta=2(sin^2theta+cos^2theta)+cos^2theta`
`=2+cos^2thetagt2 [:'cos^2thetagt0]`
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CENGAGE-TRIGONOMETRIC FUNCTIONS -Exercise (Single)
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  2. IF tan alpha = ( sin alpha - cos alpha )/( sin alpha + cos alpha)...

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  3. The least value of 2sin^2theta+3cos^2theta is 1 (b) 2 (c) 3 (d) ...

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  4. The greatest value of sin^4theta+cos^4thetai s 1/2 (b) 1 (c) 2 (d...

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  7. Range of f(theta)=cos^2theta(cos^2theta+1)+2sin^2theta is [3/4,1] (b)...

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  8. If 0<theta<pi, then minimum value of 3sintheta+cos e c^3theta is 4 (b)...

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  9. If thetaigt0" for "1lethetalenandtheta1+theta2+theta3+...+thetan=pithe...

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  10. The set of values of lambda in R such that sin^2theta+costheta=lambda...

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  11. Let A=sin^8theta+cos^14theta, " then "A("max") is

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  15. The variable x satisfying the equation |sinxcosx|+sqrt(2+tan^2 x+cot^2...

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  16. If the equation cot^4x-2cos e c^2x+a^2=0 has at least one solution, th...

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  17. If cos^2x-(c-1)cosx+2cgeq6 for every x in R , then the true set of va...

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  18. If the inequality sin^(2) x+a cos x+a^(2) gt 1+ cos x holds for any x ...

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  19. If (3pi)/4,sqrt(2cotalpha+1/(sin^2alpha)) is equal to 1+cotalpha (b) ...

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  20. The value of sectheta/sqrt(1-cos^2x)+cosx/(sqrt(1+cot^2theta))" for "...

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