Answer:
Proportional.
Step-by-step explanation:
Find the cross products. If they are same, then they are proportional.
Cross multiply,
1.2 * 4 .5 = 3*1.8
5.40 = 5.4
So, they are proportional.
Or
Multiply the numerator and denominator of 1.2/3 by 1.5
From this we come to know they are proportional
Or
1.2 : 3 :: 1.8 : 4.5
Product of means = 3*1.8 = 5.4
Product of extremes = 1.2*4.5 = 5.4
Product of means = product of extremes. So, they are proportional.
Answer:
(-∞, -2), (-2, -0.618), and (1.618, 3)
Step-by-step explanation:
The red plus (+) signs indicate the regions in which the function is concave up, and the red negative (-) signs indicate the regions in which the function is concave down.
Note that the sign of the concavity changes at an inflection point.
Let's examine the intervals given.
(-∞, -2): Yes, concave up.
(-∞, -1.17): No. Concave up in (-∞, -2) but concave down in (-2, -1.17).
(-2, 0): No. Concave down in (-2, -1.17) but increasing in (-1.17, 0.0).
(-1.17, 0.689): Yes. Concave up.
(-0.618, 1.618): No. Concave up in (-0.618, 0.689) but concave down in (0.689, 1.618).
(0, 3): No. Concave up in (0, 0.689), concave down in (0.689, 2.481), and concave up in (2.481, 3).
(2.481, ∞): Yes. Concave up.
The three intervals that are concave up are (-∞, -2), (-1.17, -0.689), and (2.481, ∞).
