iam getting the ans as x²/a² + y²/b²=2sin²cos²       am i wrong

i squared both the equations and added them

how come we get the ans



eq 1 on squaring

 

x²/a²cos²  +  y²/b²sin² = 1

eq 2 on squaring we get

x²/a²sin² +  y²/b²cos²  = 1

now if we add these two how can we get the required ans

it will come as

1/sin²cos² (x²/a² + y²/b²)=2

isnt it correct