I attached a picture, see if you can see what I'm doing. Basically, I start by squaring everything to get rid of the radical, but just remember at the end to always, always check your answers, because squaring your answers could get rid of some negative numbers that could result in imaginary answers. The answer I came up with was a=5,-2
Answer:
x∈R
Step-by-step explanation:
Answer:
Perimeter = 15
Step-by-step explanation:
We are told that the length of each of the 3 sides of the triangle are consecutive odd integers.
Thus means that we can write the 3 terms as;
(x - 2), x, (x + 2)
Thus, perimeter is;
P = (x - 2) + x + (x + 2)
P = 3x
If an angle is 120°, it means that the corresponding side that is directly opposite the angle is the largest side of the triangle.
Thus, this side is (x + 2)
Using cosine rule, we have;
(x + 2)² = x² + (x - 2)² - 2(x(x - 2))cos 120
Expanding, we have;
x² + 4x + 4 = x² + x² - 4x + 4 - (2x² + 4x)(-½)
This reduces to;
4x = x² - 4x + x² - 2x
2x² = 10x
2x = 10
x = 10/2
x = 5
Thus, other sides are;
(x - 2) = 5 - 2 = 3
And (x + 2) = 5 + 2 = 7
So,perimeter is;
P = 3x = 3 × 5 = 15
