Answer:
t=+4.06
Step-by-step explanation:
when the baseball hits the ground, the height will be 0.
h=0we are given that h=−16t2+64t+4.
this means that the height is 0 when −16t2+64t+4=0.−16t2+64t+4=0divide both sides by 4:−4t2+16t+1=04=0−4t2+16t+1=0 can be solved using the quadratic formula:t=−b±√b2−4ac2a, where at2+bt+c=0.at2+bt+c=−4t2+16t+1a=−4,b=16,c=1t=−b+√b2−4ac2aor−b−√b2−4ac2a−b+√b2−4ac2a=−16+√272−8=−0.06..−b−√b2−4ac2a=−16−√272−8=4.06 (3s.f.)we have 2 values for t:−0.06 and 4.06.
since time cannot be negative, only the positive value can be taken.
this is 4.06, to 3 significant figures.the time taken is 4.06 seconds.
Answer:
0.51 cm
Step-by-step explanation:
In right triangle MNP, MP = 4 cm, m∠N = 90°, m∠P = 21°
By the sine definition,
Now, consider right triangle HMN (it is right because NH is an altitude). By the cosine definition,
In the right triangle, two acute angles are always complementary, so
Thus,
An = a1 * r^(n-1)
n = term to find = 18
a1 = first term = 3
r = common ratio = 4/3
now we sub
a18 = 3 * 4/3^(18 - 1)
a18 = 3 * 4/3^17
a18 = 3 * 133
a18 = 399
