Plz answer immediately
1 answer:
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Answer:
Step-by-step explanation:
You have to use the discriminant for this. If the quadratic is , then
a = -4, b = -3, and c = 7. The formula for finding the discriminant is
which comes from the quadratic formula, but without the square root sign. Filling in:
which simplifies down to
D = 9 + 112 so
D = 121. This is a perfect square, so the solutions will be 2 real. Just so you know, you will NEVER have a solution like the one offered in the third choice down. If you have one imaginary root, you will ALWAYS have a second by the conjugate rule.
Answer:
When do you hit the water?
1.075 seconds after you jump.
What is your maximum height?
the maximum height is 12.5626 ft
Step-by-step explanation:
The equation:
h(t) = -16*t^2 + 6*t + 12
Is the height as a function of time.
We know that the initial height is the height when t = 0s
h(0s) = 12
and we know that the diving board is 12 foot tall.
Then the zero in h(t)
h(t) = 0
Represents the surface of the water.
When do you hit the water?
Here we just need to find the value of t such that:
h(t) = 0 = -16*t^2 + 6*t + 12
Using the Bhaskara's formula, we get:
Then we have two solutions, and we only care for the positive solution (because the negative time happens before the jump, so that solution can be discarded)
The positive solution is:
t = (-6 - 28.4)/-32 = 1.075
So you hit the water 1.075 seconds after you jump.
What is your maximum height?
The height equation is a quadratic equation with a negative leading coefficient, then the maximum of this parabola is at the vertex.
We know that the vertex of a general quadratic:
a*x^2 + b*x + c
is at
x = -b/2a
Then in the case of our equation:
h(t) = -16*t^2 + 6*t + 12
The vertex is at:
t = -6/(2*-16) = 6/32 = 0.1875
Evaluating the height equation in that time will give us the maximum height, which is:
h(0.1875) = -16*(0.1875 )^2 + 6*(0.1875) + 12 = 12.5626
And the height is in feet, then the maximum height is 12.5626 ft