Question

Find sinθ×cos^2θ when sinθ=14 and θ is in Quadrant I.

Answer 1

• Theta be A
• sinA=1/4( sin has range -1 to 1 only)

cosA:-

`\\ \rm\longmapsto √(1-sin^2A)=√(1-(1/4)^2)=√(1-1/16)=√(15/16)=(3√(5))/(4)`

• In Q1 all are positive

Now

`\\ \rm\longmapsto sinA+cos^2A`

`\\ \rm\longmapsto 1/4+15/16`

`\\ \rm\longmapsto 4+15/16=19/16`