Answer:
D
Step-by-step explanation:
Let's draw a picture (see attachment).
We know that since our point is (-5, -12), it must pass in the third quadrant. Now, if we drop a perpendicular line from the point (-5, -12) to the x-axis, we have a right triangle. Notice that we already know the two leg lengths of this: -5 and -12.
Cosine is adjacent / hypotenuse. Here, the adjacent side to the angle θ is -5. We need to find the hypotenuse, which we can do so by using the Pythagorean Theorem:
c² = a² + b²
c² = (-5)² + (-12)²
c² = 25 + 144 = 169
c = 13
So, the hypotenuse is 13. Now, plug these values in:
cos(θ) = adjacent / hypotenuse = -5/13
The answer is D.
Answer:
f(5) = -2
Step-by-step explanation:
f (x) = -x + 3
Let x = 5
f(5) = -5+3
f(5) = -2
Answer:
Option A
Step-by-step explanation:
Sin(x) is the same value as cos(y) in the graph.
Answer:
See below
Step-by-step explanation:
Let side AB equal x. Since triangle ABC is equilateral, sides AB, BC, and Ac are all the same length, x. In any isosceles triangle(equilateral is a type of isosceles triangle) the median is the same as the altitude and angle bisector. This means we can say that AD is also a median. A median splits a side into two equal sections, so we can say BD = DC = x / 2. We are given that DC = CE, so we can also say CE = DC = x / 2. Now, we can use the pythagorean theorem to find the length of AD. So we get the equation:
AB^2 - BD^2 = AD^2
We have the values of AB and BD, so we can substitute them and solve for AD:
x^2 - (x/2)^2 = AD^2
x^2 - x^2 / 4 = AD^2
AD^2 = 3x^2 / 4
AD = x√3 / 2
DE is equal to the sum of DC and CE because of segment addition postulate, so we can say DE = DC + CE = x / 2 + x/ 2 = x. We can again use the pythagorean theorem to find the length of AE:
AD^2 + DE^2 = AE^2
(x√3 / 2)^2 + x^2 = AE^2
3x^2 / 4 + x^2 = AE^2
AE^2 = 7x^2 / 4
AE = x√7 / 2
Now, we know(from before) that AE squared is 7x^2 / 4. We can say EC squared is x^2 / 4 because EC is x / 2 and x / 2 squared is x^2 / 4. We can also notice that AE squared is 7 times EC squared because 7x^2 / 4 = 7 * x^2 / 4
Therefore, we can come to the conclusion AE^2 = 7 EC^2
Answer:
1. If x is under a square root then x cannot equal a negative number. If x is in the denominator of a fraction then x cannot equal zero.
2. ax2 + bx + c
Step-by-step explanation: Hope this helps :)