Domain and Range of the Inverse Quadratic Function

* I need help on this subject, if you could explain i'll be very happy. *

1) Graph g(x) = - √x for x > 0

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State the domain and range of $\displaystyle g^-1 (x)$

2) $\displaystyle h(t) = -5t^2 +10t+35$ where h(t) is the heigh above the ground in metres at time t seconds after it is thrown.

determine the domain and range of h(t).

3) for $\displaystyle -2 < x < 3$ and $\displaystyle f(x) = 3x^2 - 6x$

determine the domain and range of f(x)

4) consider $\displaystyle f(x) = -2x^2 +3x -1

$

determine the domain and range of $\displaystyle f^-1 (x) for y > 0.75$

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I really need help with this questions. If you could explain this to me i'll be very happy. Thank you for your helps.