If xtan60° + cos45° = sec45°, then the value of x2 + 1 is?
A. $$\frac{6}{7}$$
B. $$\frac{7}{6}$$
C. $$\frac{5}{6}$$
D. $$\frac{6}{5}$$
Answer: Option B
Solution(By Examveda Team)
$$\eqalign{ & \Rightarrow x\tan {60^ \circ } + \cos {45^ \circ } = \sec {45^ \circ } \cr & \Rightarrow x.\sqrt 3 + \frac{1}{{\sqrt 2 }} = \sqrt 2 \cr & \Rightarrow x\sqrt 6 + 1 = 2 \cr & \Rightarrow x = \frac{1}{{\sqrt 6 }} \cr }$$Squaring both sides and addition 1 both sides
$$\eqalign{ & \Rightarrow {x^2} + 1 = {\left( {\frac{1}{{\sqrt 6 }}} \right)^2} + 1 \cr & \Rightarrow {x^2} + 1 = \frac{1}{6} + 1 \cr & \Rightarrow {x^2} + 1 = \frac{7}{6} \cr} $$
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