Answer:
The answer to your question is 14° and 76°
Step-by-step explanation:
Data
leg 1 = x
leg 2 = x/4
angle 1 = ?
angle 2 = ?
Process
To solve problem use trigonometric functions. We must use the trigonometric function that relates both legs (tangent).
tangent Ф = Opposite side / Adjacent side
-Substitution
tan Ф = (x/4) / x
-Simplification
tan Ф = x / 4x
tan Ф = 1/4
- Find Ф
Ф = tan⁻¹(1/4) = 14°
- Find the other acute angle
The sum of the internal angles in a triangles equals 180°
Ф + Ф₁ + 90° = 180
-Solve for Ф₁
Ф₁ = 180 - 90 - 14
-Result
Ф₁ = 76°
Answer:
-2, 8/3
Step-by-step explanation:
You can consider the area to be that of a trapezoid with parallel bases f(a) and f(4), and width (4-a). The area of that trapezoid is ...
A = (1/2)(f(a) +f(4))(4 -a)
= (1/2)((3a -1) +(3·4 -1))(4 -a)
= (1/2)(3a +10)(4 -a)
We want this area to be 12, so we can substitute that value for A and solve for "a".
12 = (1/2)(3a +10)(4 -a)
24 = (3a +10)(4 -a) = -3a² +2a +40
3a² -2a -16 = 0 . . . . . . subtract the right side
(3a -8)(a +2) = 0 . . . . . factor
Values of "a" that make these factors zero are ...
a = 8/3, a = -2
The values of "a" that make the area under the curve equal to 12 are -2 and 8/3.
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<em>Alternate solution</em>
The attachment shows a solution using the numerical integration function of a graphing calculator. The area under the curve of function f(x) on the interval [a, 4] is the integral of f(x) on that interval. Perhaps confusingly, we have called that area f(a). As we have seen above, the area is a quadratic function of "a". I find it convenient to use a calculator's functions to solve problems like this where possible.
Answer:
option 2
Step-by-step explanation:
a colored in dot is less than or equal to or greater than or equal to while an uncolored dot is less then or greater than. arrow going left of the number is less than arrow going right is greater than. the problem is a is greater than 4/5 so an uncolored dot shout be on 4/5 going to the right