1) Given a quadratic function y = 2x^2 - 6x + 7, find the coordinates of the vertex by using the method of completing the square.

Mr F says: . So complete the square on (see below) and then multiply the result the result by 2.
2) A stone was thrown vertically upwards from the ground. Its height above the ground, s meters, reached in t seconds was given by

s = -5t^2 + 40t

a) Express s in the form a(t - b)^2 + c, where a, b and c are constants.

Mr F says: . So complete the square on (see below) and then multiply the result the result by -5.
b) What is the greatest height reached and the time to obtain this height?

Mr F says: y-coordinate of turning point and t-coordinate of turning point.
Please help and explain concepts. Thanks.