Question

solve the equation cos square x +sinx =5/4​

Answer 1

Answer :

x = 30°

Explanation :

cos²x +sinx = 5/4

=> 1-sin²x + sinx = 5/4

=> 4(1-sin²x+sinx) = 5

=> 4-4sin²x+4sinx=5

=> -4sin²x+4sinx-1 = 0

=> -(4sin²x-4sinx+1)=0

=>4sin²x-4sinx+1=0

=> (2sinx)²-2*2sinx*1+1²=0

=>(2sinx-1)² =0

=> 2sinx-1= 0 or 2sinx-1 = 0

=> sinx = 1/2 or sinx = 1/2

=> sinx = sin30

=> x =30°

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