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# Exercise 3.12: Choose the correct or the most suitable answer

Multiple choice questions with answers / choose the correct answer with answers - Maths Book back 1 mark questions and answers with solution for Exercise Problems - Mathematics : Trigonometry

CHAPTER : Trigonometry

1. 1/cos 80╠Ŗ  - ŌłÜ3/sin 80╠Ŗ =

(1) ŌłÜ2

(2) ŌłÜ3

(3) 2

(4) 4

Solution 2. If cos 28╠Ŗ  + sin 28╠Ŗ  = k3, then cos 17╠Ŗ  is equal to

(1) k3/ŌłÜ2

(2) -k3/ŌłÜ2

(3) ┬▒ k3/ŌłÜ2

(4) - k3/ŌłÜ2

Solution 3. The maximum value of 4 sin2x + 3cos2x + sin x/2 + cos x/2 is

(1) 4 + ŌłÜ2

(2) 3 + ŌłÜ2

(3) 9

(4) 4

Solution 4. (1) 1/8

(2)1/2

(3)1/ŌłÜ3

(4)1/ŌłÜ2

Solution 5. If , equal to

(1) -2cos╬Ė

(2) -2sin╬Ė

(3) 2cos╬Ė

(4) 2sin╬Ė

Solution (Option : (4) 2sin╬Ė or (1) -2cos╬Ė ??????? Please don't refer this solution for examination) 6. If tan40╠Ŗ = ╬╗, then (1) 1-╬╗2/ ╬╗

(2) 1+╬╗2/ ╬╗

(3) 1+╬╗2/ 2╬╗

(4) 1-╬╗2/ 2╬╗

Solution 7. cos 1╠Ŗ + cos 2╠Ŗ + cos 3╠Ŗ + ŌĆ”. + cos 179╠Ŗ =

(1) 0

(2) 1

(3) -1

(4) 89

Solution 8. Let fk(x) =1/k [sinkx + coskx] where x ŌłŖ R and k Ōēź 1. Then f4(x) - f6(x) =

(1)1/4

(2)1/12

(3)1/6

(4)1/3

Solution 9. Which of the following is not true?

(1) sin ╬Ė = -3/4

(2) cos ╬Ė = -1

(3) tan ╬Ė = 25

(4) sec ╬Ė =1/4

Solution 10. cos2╬Ė cos2ŽĢ + sin2 (╬Ė - ŽĢ) - sin2 (╬Ė + ŽĢ) is equal to

(1) sin 2(╬Ė + ŽĢ)

(2) cos 2(╬Ė + ŽĢ)

(3) sin 2(╬Ė - ŽĢ)

(4) cos 2(╬Ė - ŽĢ)

Solution 11. (1) sinA + sinB + sinC

(2) 1

(3) 0

(4) cosA + cosB + cosC

Solution 12. If cos p╬Ė + cos q╬Ė = 0 and if p ŌēĀ q, then ╬Ė is equal to (n is any integer) Ans: 2

Solution 13.If tan╬▒ and tan╬▓ are the roots of x2 + ax + b = 0, then is equal to

(1)b/a

(2)a/b

(3) ŌĆōa/b

(4) ŌĆōb/a

Solution 14. In a triangle ABC, sin2A + sin2B + sin2C = 2, then the triangle is

(1) equilateral triangle

(2) isosceles triangle

(3) right triangle

(4) scalene triangle.

Solution 15. If f(╬Ė) = |sin ╬Ė| + |cos╬Ė| , ╬Ė ŌłŖ R, then f(╬Ė) is in the interval

(1) [0, 2]

(2) [1,ŌłÜ2]

(3) [1, 2]

(4) [0, 1]

Solution 16. cos 6x + 6 cos 4x + 15 cos 2x + 10 / cos 5x + 5 cos 3x + 10 cos x is equal to

(1) cos2x

(2) cos x

(3) cos 3x

(4) 2 cos x

Solution 17. The triangle of maximum area with constant perimeter 12m

(1) is an equilateral triangle with side 4m

(2) is an isosceles triangle with sides 2m, 5m, 5m

(3) is a triangle with sides 3m, 4m, 5m

(4) Does not exist.

Solution 18. A wheel is spinning at 2 radians/second. How many seconds will it take to make 10 complete rotations?

(1) 10ŽĆ seconds

(2) 20 ŽĆ seconds

(3) 5 ŽĆ seconds

(4) 15ŽĆ seconds

Solution 19. If sin╬▒ + cos╬▒ = b, then sin 2╬▒  is equal to

(1) b2 - 1, if b Ōēż ŌłÜ2

(2) b2 - 1, if b > ŌłÜ2

(3) b2 - 1, if b Ōēź 1

(4) b2 - 1, if b ŌēźŌłÜ2

Solution 20. In a ŌłåABC, if

(i) sin A/2 sin B/2 sin C/2> 0

(ii) sinAsinB sinC > 0 then

(1) Both (i) and (ii) are true

(2) Only (i) is true

(3) Only (ii) is true

(4) Neither (i) nor (ii) is true.

Solution Tags : Trigonometry | Mathematics , 11th Mathematics : UNIT 3 : Trigonometry
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11th Mathematics : UNIT 3 : Trigonometry : Exercise 3.12: Choose the correct or the most suitable answer | Trigonometry | Mathematics