SOLUTION: what is the answer to the answer? a cricket ball is hit directly upwards. its height above ground, h meters, after t seconds, is given by {{{ h=-4t^2+40t }}} I have to det

Algebra ->  Coordinate-system -> SOLUTION: what is the answer to the answer? a cricket ball is hit directly upwards. its height above ground, h meters, after t seconds, is given by {{{ h=-4t^2+40t }}} I have to det      Log On


   

Question 1046742: what is the answer to the answer?
a cricket ball is hit directly upwards. its height above ground, h meters, after t seconds, is given by +h=-4t%5E2%2B40t+
I have to determine the coordinates for the axis intercepts.
so i got
+let+h=0+
+0=-4t%5E2%2B40t+
my teacher got this, but i don't know how and i need it for my exam tomorrow
+h=4t%28-t%2B10%29+
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
That was simple factorization. Use Zero-Product principle from that.


--
The two cartesian number lines would be h for vertical and t for horizontal number lines. h is for height of the ball. The horizontal axis intercepts for be the values for t when h is zero, or for h=0. This justifies making h=0=-4t%5E2%2B40t
and then
Multiply "both" members by -1%2F4 to get
0=t%5E2-10t
t%5E2-10t=0
t%28t-10%29=0

ZERO-PRODUCT PRINCIPLE!
Let x and y be real numbers.
If xy=0, then either x=0, or y=0, or x=y=0.