FIRST PARTWe need to find sin α, cos α, and cos β, tan β
α and β is located on third quadrant, sin α, cos α, and sin β, cos β are negative
Determine ratio of ∠α
Use the help of right triangle figure to find the ratio
tan α = 5/12
side in front of the angle/ side adjacent to the angle = 5/12
Draw the figure, see image attached
Using pythagorean theorem, we find the length of the hypotenuse is 13
sin α = side in front of the angle / hypotenuse
sin α = -12/13
cos α = side adjacent to the angle / hypotenuse
cos α = -5/13
Determine ratio of ∠β
sin β = -1/2
sin β = sin 210° (third quadrant)
β = 210°

SECOND PARTSolve the questions
Find sin (α + β)
sin (α + β) = sin α cos β + cos α sin β



Find cos (α - β)
cos (α - β) = cos α cos β + sin α sin β



Find tan (α - β)


Simplify the denominator


Simplify the numerator


Simplify the fraction

Answer:
0.8686 or 86.86 %
0.2148 or 21.48 %
Step-by-step explanation:
In z table the value of z > - 1,12 is 0.1314 (value from the z point to the left of the curve ) then 1 - 01314 will be value from z point to the right
Again from z table we get for z = - 0.79 the value 0.2148 s the vale from the point up to the left tail
Answer:
...........the answer is 7?!
We have to find the parameter a so that (-1,2) is part of the function f(x) = ax²+4.
To check if a point is part of a function, we can replace the values of x and y = f(x) with the coordinates of the point and then, if the equation stays true, then the point is part of the function.
So for (x,y) = (-1,2) to be part of the function y = f(x), this equation has to stands true:

Then, the function would have to be f(x) = -2x² + 4.
We can check with a graph as:
Answer: a = -2