Let θ be an angle such that sinθ=3 over 4 and cotθ<0 Find the exact values of tanθ and cosθ?
回答 (1)
2016-11-06 7:53 pm
sin θ = 3/4 =opp/hyp
adj = sqrt(4^2 -3^2) = sqrt(16-9)=sqrt(7)
cot θ < 0 so the angle lies in quadrant II
tan θ = opp/adj = -3/sqrt(7) ----(tan is negative in quadrant II)
cos θ = adj/hyp = -sqrt(7)/4 ---- (cos is negative in quadrant II)
adj = sqrt(4^2 -3^2) = sqrt(16-9)=sqrt(7)
cot θ < 0 so the angle lies in quadrant II
tan θ = opp/adj = -3/sqrt(7) ----(tan is negative in quadrant II)
cos θ = adj/hyp = -sqrt(7)/4 ---- (cos is negative in quadrant II)
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