Answer:
28
Step-by-step explanation:
28 = 7 x 4
So,
7 is a factor of 28.
cos (2x) = cos x
2 cos^2 x -1 = cos x using the double angle formula
2 cos ^2 x -cos x -1 =0
factor
(2 cos x+1) ( cos x -1) = 0
using the zero product property
2 cos x+1 =0 cos x -1 =0
2 cos x = -1 cos x =1
cos x = -1/2 cos x=1
taking the arccos of each side
arccos cos x = arccos (-1/2) arccos cos x = arccos 1
x = 120 degrees x=-120 degrees x=0
remember you get 2 values ( 2nd and 3rd quadrant)
these are the principal values
now we need to add 360
x = 120+ 360n x=-120+ 360n x = 0 + 360n where n is an integer
Answer:
A
Step-by-step explanation:
-x + 2y = 8
5x + 2y = -4
+ x. -2y. -8
6x = -12
÷6. ÷6
x = -2
5(-2) + 2y = -4
-10 + 2y = -4
+10. +10
2y = 6
÷2. ÷2
y = 3
Answer:
x
=
11.12130872
Step-by-step explanation:
if this isnt right then let me know
The slopes of lines perpendicular to each other are opposite reciprocals. So, if you are given that the slope of a line is 3 and need to find the slope of a line perpendicular to that line, you'd flip that number around and negate it, leaving you with -1/3.
To find the slope of the given line, first get it into slope-intercept form (y - mx + b, where m is the slope and b is the y-intercept).
3y = -4x + 2
y = -4/3x + 2/3
The slope is -4/3. To find the slope of a perpendicular line, find its opposite reciprocal. It is 3/4.
Answer:
3/4 (the first option)
