The desired number is the difference between the number of messages sent by the 16th day and the number sent by the 9th day:
... n = t(16) - t(9)
... n = (40×√16) - (40×√9)
... n = 40×(4 - 3) = 40
40 text messages were sent between the ninth and sixteenth day of the month.
Answer:
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Step-by-step explanation:
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Answer:
Step-by-step explanation:
Let's first put that polynomial in standard form by descending powers of t:
If we are looking for the times where the rocket is at a height of 26 m, we sub in a 26 for h(t) and factor to solve for t. First we get all the terms on one side of the equals sign and set it equal to zero.
That is a second degree polynomial so you can factor it however you are most comfortable to get the values of t are:
t = .51 sec and t = 10.29 sec
Since this is a polynomial, there will be 2 values of t for this time with y being the height and x being the time. The parabola is symmetrical about the vertex so there are 2 values of t (or x) that equal height (or y).