Answer:
2 cm^2/sec
Step-by-step explanation:
side of cube ---- x cm
volume = x^3
d(volume)/dt = 3x^2 dx/dt
when c = 20, d(volume)/dt = 10 cm^3/sec
10 = 3(20^2) dx/dt
dx/dt = 10/1200 = 1/120 cm/sec
Surface area = SA = 6x^2
d(SA)/dt = 12x dx/dt
so when x = 20, as above
d(SA)/dt = 12(20)(1/120) cm^2/sec
= 2 cm^2/sec
<span>let landmark be at L
ZN = 100, NL = x (say)
tan 54 = (100+x)/H
100 + x = H tan 54 -------------- (1)
------------------------------
tan 61 = H/x ................ [alternate angle]
x = H cot 61 ------------------------- (2)
put x from (2) into (1)
H cot 61 + 100 = H tan 54
H = 100 / [tan 54 -cot 61]
H = 100 / [1.376 - 0.554]
H = 121.65 feet</span><span>
</span>
They are equally spaced so all the circles share the same center point.
I don't think it really matters if the denominator is negative in a literal equation. Think about a simpler example with numbers. Does it matter whether a fraction is -1/2 or 1/-2? No, they are both the same. Therefore, I would say that the denominator of a literal equation can be negative.
Good luck with your exams!
1 1/2 or 3/4
either or should work