Answer:
8² = 4² + 5² - 2(4)(5) cos(P)
which is the third option
Explanation:
The general rule of cosine is:
a² = b² + c² - 2bc*cos(A)
In our triangle:
a is substituted by p = 8 cm
b is substituted by n = 4 cm
c is substituted by m = 5 cm
A is substituted by P which we want to find
Replace the variables in the general equation with the givens as follows:
p² = n² + m² - 2mn*cos(P)
8² = 4² + 5² - 2(4)(5) cos(P)
Hope this helps :)
I’m not 100 percent sure someone can comment on this and confirm but when it’s written like a fraction it means division. If they gave you the meaning of each variable (the letters) multiply each variable by each coefficient (the number next to the variable). Multiply all of those. Then divide it by the product of 4 and the variable
Hope this helped!
Look carefully at the first pair: (−3, 9), (−3, −5) Note that x does not change, tho' y does. This is how we recognize a vertical line (whose slope is undefined). The equation of this vertical line is x = -3.
Looking at the second pair: from (3,4) to (5,6), x increases by 2 and y by 2; thus, the slope is m = rise/run = 2/2 = 1.
Third pair: as was the case with the first pair, x does not change here, and thus the equation of this (vertical) line is x=0 (which is the y-axis). The slope is undefined.
