Arocket on a computer screen has a path modeled by the equation h=-t2+3t+10 where t is time in seconds and h is the height above a platform and is in computer units. find how long the rocket takes to reach the platform.
a - 2 seconds
b - 10 seconds
c - 12 seconds
d - 5 seconds

When the rocket reaches the platform, then h must be equal to 0

h=0

Calculating for t using the equation:

h=-t^2+3t+10

0 = -t^2+3t+10
reversing sides: 
t^2 -3t -10 = 0 

By completing the squares or factoring, we can get the roots: 

(t-5)(t+2) =0 
t=5 or t=-2 

Since time cannot be negative, therefore: 

t = 5 seconds 

Answer is D.

The time taken by the rocket to reach the platform is 5 seconds.

According to the question, the path model of the rocket on the computer screen is where, is time in seconds and is the height above the platform.

If the rockets reaches to the platform then, the height above the platoform for the rocket must be equals to zero.

So,

Hence, the time taken by the rocket to reach the platform is 5 seconds.

Learn more about quadratic equations here:

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the camry sales+accord sale=828,000. to make it so the two numbers are 18 thousand apart and still equal 828,000, you first need to find out what half of 828,000 is. 828,000/2=414,000. for the two numbers to equal 828,000, you have to add the same amount as you subtract from the middle. in this case, the number is 9,000 because it's half of 18,000. to equal 828,000, you have to add 9,000 to 414,000 for the camry and subtract 9,000 from 414,000 for the accord. 414,000+9,000=423,000.

414,000-9,000=405,000.

423,000+405,000=828,000.

423,000-405,000=18,

hope it