2010 · Q11
Which one of the following is correct ?
Elementary MathematicsTrigonometry
- AThere is only one θ with 0° <θ < 90° such that sin θ = a, where a is a real number
- BThere is more than one θwith 0° < θ < 90° such that sin θ= a, where a is a real number
- CThere is no θwith 0° <θ < 90° such that sinθ = a, where a is a real number
- DThere are exactly twoθ s with 0° < θ < 90° such that sin θ = a, where a is a real number
Explanation
sin θ is strictly increasing on (0°,90°), so sin θ=a has at most one solution there.