Answer:
Step-by-step explanation:
h = -6
+20t + 4
I will use calculus, maybe that's not how you're supposed to do this
-12t +20 =0
12t = 20
t = 20 /12
t = 1 
t = 1 
there will be a max at 1.6666666666 seconds
-6*
+ 20 * 1.6666666666 +4
= 16.666666666666 + 33.333333333333 + 4
= - 16
+ 33
+ 4
= 20
feet max height ( not too high, for a rocket)
time of flight:
0 = -6
+20t + 4
use quadratic formula to find t
-20 +- sqrt [
- 4*(-6)*4 ] / 2*(-6)
-20 +- sqrt [400 + 96 ] / -12
-20 +- sqrt [496 ] / -12
-20 +- 22.27105 / -12
try the negative option 1st
-42.27105 / -12
3.522 seconds. time of flight
when will the rocket be at 12' ? :
12 = -6
+20t + 4
0 = -6
+20t -8
use quadratic formula again to find t
-20 +- sqrt [
- 4*(-6)*(-8) ] / 2*(-6)
-20 +- sqrt [ 400 - 192 ] / -12
-20 +- sqrt [208 ] / -12
-20 - 14.4222 / -12
-34.4222 / -12
2.8685 seconds ( on the way down)
and
-20 + 14.4222 / -12
-5.578 / - 12
0.4648 seconds ( on the way up )
Answer: Answer choices 1, 3, 4
Step-by-step explanation:
As long as it ends in .0, .2, .4, .6, or .8 it's fine. Therefore the first and last 2 work, since 0.2 can end in either of those 5 values.
Hope that helped,
-sirswagger21
Answer:
The answer is a. 21.
Step-by-step explanation:
We solve this question by using Pythagoras theorem to relate the sides of a right angled triangle.
Here,
Hypotenuse of the given triangle(c)=75
Two sides of right angled triangle are:
a=72
b=?
Then,
for a given right angled triangle abc,
Using Pythagoras theorem,

Squaring on both sides,

or,
or, 
or,
or,
∴
So, the value of b is obtained to 21 by the use of Pythagoras theorem.