51×59 evaluate and answer
2 answers:
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Answer:
A. y = 2x -9
B. y = -1/2x +1
Step-by-step explanation:
The given line is in slope-intercept form
y = mx + b
where m is the slope. For your given line, the slope is 2.
A. A parallel line will have the same slope. It is convenient to start with a point-slope form of the equation for the line:
y = m(x -h) +k . . . . . for slope m through point (h, k)
You want the equation of the line through (4, -1) with slope 2, so its equation is ...
y = 2(x -4) -1
Simplifying to slope-intercept form, this becomes ...
y = 2x -8 -1
y = 2x -9
___
B. A perpendicular line will have a slope that is the opposite of the reciprocal of the slope of the given line. That slope is ...
m = -1/2
As above, the point-slope form of the perpendicular line is ...
y = -1/2(x -4) -1
y = -1/2x +1 . . . . . after simplification
The solutions appear to be {π/2, 2π/3, 4π/3}.
_____
Replacing sin(2x) with 2sin(x)cos(x), you have
2sin(x)cos(x) +sin(x) -2cos(x) -1 = 0
sin(x)(2cos(x) +1) -(2cos(x) +1) = 0 . . . . factor by grouping
(sin(x) -1)(2cos(x) +1) = 0
This has solutions
sin(x) = 1
x = π/2
and
2cos(x) = -1
cos(x) = -1/2
x = {2π/3, 4π/3}
_____
Replacing sin(2x) with 2sin(x)cos(x), you have
2sin(x)cos(x) +sin(x) -2cos(x) -1 = 0
sin(x)(2cos(x) +1) -(2cos(x) +1) = 0 . . . . factor by grouping
(sin(x) -1)(2cos(x) +1) = 0
This has solutions
sin(x) = 1
x = π/2
and
2cos(x) = -1
cos(x) = -1/2
x = {2π/3, 4π/3}