Fraction form of the ratio a is to b is :
ba
ab1
ab
a×1b×1
“ a” is to “b” indicates that first term “a” should be in the numerator of the fraction.
And
Second term “b” should be in the denominator of the fraction.
So, the answer is : ab
tan−1a+tan−1b, where a>0,b>0,ab>1, is equal to