Answer:
true
Step-by-step explanation:
sinA² + cosA²=1
⇔(1/2)² + cosA²=1
⇔cosA=±(√3/2)
The first equation is x = -1
The second and third equations are no solution
The third equation is all rel numbers.
We can tell each one by solving them. In the first one, you get the following.
4 + x = -8x - 5 ----> Add 8x to both sides
4 + 9x = -5 ----> Subtract 4 from both sides
9x = -9 ----> Divide both sides by 9
x = -1
For the middle two, when you attempt to solve, you get untrue statements. This shows there are no solutions. See the example below.
7 + 2x = 2x - 7 ----> Subtract 2x from both sides
7 = -7 (UNTRUE)
And for the last one, each term cancels out, which shows that we have all real solutions.
-3x + 3 = 3( 1 - x) ----> Distribute the 3
-3x + 3 = 3 - 3x ----> Add 3x to both sides
3 = 3 (TRUE)
Answer:
x = 81, y = 68, z = 99
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Consider the triangle on the left, then
x = 180 - (36 + 63) = 180 - 99 = 81
The exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.
x is an exterior angle of the triangle on the right, thus
13 + y = x , that is
13 + y = 81 ( subtract 13 from both sides )
y = 68
Consider the triangle on the right
z = 180 - (13 + y) = 180 - (13 + 68) = 180 - 81 = 99
According to Desmos Graphing Calculator none of these equations passes threw the points (-5,2) and (10,-1)
