If the stack is 21ins and each board is 1 3/2 ins thick that means you 21/(1 3/2) so you end up getting 8.4. Because you can't have a part of a board you round the number down to 8 boards.
Answer:
Find the 40th term for the arithmetic sequence in which
a8=60 and a12=48 .
Substitute 60 for a8 and 48 for a12 in the formula
an=a1+(n−1)d to obtain a system of linear equations in terms of a1 and d .
a8=a1+(8−1)d→60=a1+7da12=a1+(12−1)d→48=a1+11d
Subtract the second equation from the first equation and solve for d .
12=−4d−3=d
Then 60=a1+7(−3) . Solve for a .
60=a1−2181=a1
Now use the formula to find a40 .
a40=81+39(−3)=81−117=−36 .
Step-by-step explanation:
Answer:
53
Step-by-step explanation:
i used an angle of 45 degrees.
Distance from ground = 3feets
Angle = 45⁰
U is the initial velocity = 80ft/sec
g = 32
The question wants us to vfind maximum height
We have
r(t) = (80cos45⁰)ti + [3 + 80sin45⁰]t - 0.5(32)t²
We know cos 45 is also sin45 = 1/√2
r(t) = (40√2)ti + [3+40√2]t - 16t²
When we differentiate with respect to t:
r'(t) = (40√2)i + (40√2 - 32t)
= 40√2 =32t
t = 40√2/32
t= 20√2/16
We put the value of t into (3 + 40√2)t -16t²
When we substitute and simplify this we have
3 + 56.57 + 1.77 -16 +8
= 53.34
Which is approximately 53.
10
make a triangle after the first square and a square after the second printed triangle, then a triangle after that and after the last printed square a triangle
11
3, 4, 3, 3, 4
12
repeating
