Alvin throws the football to a receiver who jumps up to catch the ball. The height of the ball over time can be represented by the quadratic equation -4.9t^2 + 7.5t + 1.8 = 2.1 . This equation is based on the acceleration of gravity -4.9 m/s^2, the velocity of his pass is 7.5 m/s and releases the football at a height of 1.8 meters, and the height where the receiver catches the ball of 2.1 meters. Put the equation in standard form and then solve by using the quadratic equation.

I don't understand any of this, could someone help me figure out how to put it in both the standard form and quadratic equation.

2 answers

-4.9t^2 + 7.5t + 1.8 = 2.1

we usually start with a positive square term

4.9t^2 - 7.5t + 0.3 = 0

for a quadratic in the standard form of
ax^2 + bx + c = 0
x = (-b ± √(b^2 - 4ac) )/(2a)

sub in the corresponding values from my equation and find x
Okay, I did what you said and for x I got= -5.43152 now do I sub that into the top equation but instead of x I put it in for t?