Answer:
-124
Step-by-step explanation:
The equation for a discriminant is:
So for
a = 7 b = - 4 c = 5
Plug values into the equation.
16 - 140 = -124
How many 4 digit EVEN numbers can be made using the numbers 0, 1, 2, 3 (repetition allowed)
1 answer:
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Answer:
is the angle of elevation from the boat to the lighthouse.
Step-by-step explanation:
From the boat, the angle through which you will raise your head to see the light house is the angle of elevation, which is .
See graph for the illustration.
The correct answer is A
Answer:
The diameter of the model is 14.4 inches.
Step-by-step explanation:
The Diameter of the moon = 2,160 miles
The scale on the model represents 1 in = 150 miles
Let the model represents k inches in 2,160 miles.
So, by the Ratio of Proportionality:
⇒
or, k = 14.4 inches
⇒On the scale 2160 miles is represented as 14.4 inches
Hence the diameter of the model is 14.4 inches.
Answer:
174 units²
Step-by-step explanation:
There are a few different ways you can find the altitude of the trapezoid. Consider the attached figure with some points and lines added. SQ' is parallel to TQ, so Q'Q = 4 and PQ' = 21. Based on the side length of PS = 13, you can <u>guess</u> that the height is 12. (5-12-13 is a commonly-used Pythagorean triple.) This would make PP' = 5, P'Q' = 16, and triangle SP'Q' have side lengths 12, 16, and 20, corresponding to a 3-4-5 right triangle multiplied by 4.
Another way to find the height is to use Heron's formula for the area of triangle PSQ'. The side lengths are 13, 20, 21, so the half-perimeter is 27 and the area is √(27(27-13)(27-20)(27-21)) = √(9²·14²) = 126. The base of the triangle, PQ', is 21, so the height is ...
... h = 2A/b = 2·126/21 = 12
The area of parallelogram Q'STQ is then ...
... A = bh = 4·12 = 48
and the total area is the triangle area plus the parallelogram area:
trapezoid area = 126 + 48 = 174 . . . . units²
_____
Of course, with the height known, the usual formula for the area of a trapezoid can be used:
A = (1/2)(b1 +b2)h
A = (1/2)(25 +4)·12 = 29·6 = 174 . . . . units²
