`a^2 = ( a/2 )^2 + h^2` , find the value of h

If h=(V)/(A),h=5 , and V= 60cm^(3) , then find the value of A ("in" cm^(2)) .

If f,\ g,\ h are real functions defined by f=sqrt(x+1),\ g(x)=1/x\ a n d\ h(x)=2x^2-3, then find the values of (2fg+g-h)(1)\ a n d\ (2f+g-h)(1)dot

If H be the harmonic mean of a and b then find the value of H/a+H/b-2