The angle between the diagonals of a quadrilateral formed by the lines `x/a+y/b=1,x/b-y/a=1,` is

Explanation

Given `x/a + y/b = 1 …(i)`
with slope, `m_1 = -b/a`


`x/a – y/b = 1 …(ii)`
with slope, `m_2 = b/a`


We know the angle between two lines `tan theta = |(m_2 – m_1)/(1 + m_1m_2)|
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