[填空题]
A toy racing car is driving over*8r,s4y7hh8lh01l t sbarl x p a v7rhegjfs 361qv ;zva6 e)ob3 hill on a path that can be modelled by part of the functioh; 63jeqr ov3ba76vzfv)1 sgen
f(x)=-$\frac{1}{4}x^2+5$.
1.Find the gradient of the hill at the point where x=2.
f'(2)=- .
2.Find the x value of the point where the gradient perpendicular to the hill is equal to $\frac{3}{2}$.
the number is $\frac{a}{b}$ ,a= , b= .
