The elimination of θ from x cosθ - y sinθ = 2 and x sinθ + y cosθ = 4 will give?
A. x2 + y2 = 20
B. 3x2 + y2 = 20
C. x2 - y2 = 20
D. 3x2 - y2 = 10
Answer: Option A
Solution(By Examveda Team)
$$\eqalign{ & xsin\theta + y\cos \theta = 4 \cr & \underline {x\cos \theta - y\sin \theta = 2} {\text{ }}\,\,\,\,\left[ {{\text{Formula}}} \right] \cr & \left( {{x^2} + {y^2}} \right)\left( {{\text{co}}{{\text{s}}^2}\theta + {{\sin }^2}\theta } \right) = {4^2} + {2^2} \cr & \Rightarrow {x^2} + {y^2} = {a^2} + {b^2} \cr & \Rightarrow \left( {{x^2} + {y^2}} \right)\left( 1 \right) = 16 + 4 \cr & \Rightarrow {x^2} + {y^2} = 20 \cr} $$Related Questions on Trigonometry
A. x = -y
B. x > y
C. x = y
D. x < y
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