height of ball thrown = h
t = time in seconds
h = -4.9t^2 + 38t + 1.75
what is the time of the ball when h = 50
I need to be able to solve it by factoring? i can do it if the numbers 4.9 and 38 have a common denominator but can not do when they are decimals?
any help appreciated
I suppose you could plug in 50 for h, then subtract 50 from both sides
should look something like
-4.9t^2 + 38t - 48.25 = 0
Then just use the quadratic formula to find the two roots of this equation. Using those two roots, you can find the factors of the polynomial. One of those roots will be your time, (the positive one).
The quadratic formula will find your factors, however this is a bit redundant, since to find the factors you will need to find the roots, and one of the roots is your answer.
Otherwise you could use the decomposition method shown here: How to Factor Second Degree Polynomials (Quadratic Equations) - wikiHow