Mathematics

Problem

A ball is thrown upwards and its height (in metres) after

t

seconds is given by

h = -t^{2} + 6t + 7

. Which of the following triples correctly lists the opening direction of the parabola, its y–intercept, and the

x

–intercepts? a) Opens upwards; y–intercept

(0,7)

;

x

–intercepts

(-1,0)

and

(7,0)

b) Opens downwards; y–intercept

(0,7)

;

x

–intercepts

(1,0)

and

(7,0)

c) Opens downwards; y–intercept

(0,7)

;

x

–intercepts

(-1,0)

and

(7,0)

d) Opens downwards; y–intercept

(0,-7)

;

x

–intercepts

(-1,0)

and

(7,0)