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Find the equation of the line that contains the point (4, -2) and is perpendicular to the line y = - 2x + 8.

y=2x-10
1
○ y=-2/x
y=2x-4
y = -2x+6

User Miles Fett
by
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1 Answer

3 votes

Answer:

Equation of the line: y = 1/2x - 4

Explanation:

Identifying the form of y = -2x + 8:

  • Knowing the form of y = -2x + 8 will be helpful in finding the equation of the other line.

y = -2x + 8 is in the slope-intercept form of a line, whose general equation is given by:

y = mx + b, where:

  • m is the slope,
  • and b is the y-intercept.

Thus, the slope of y = -2x + 8 is -2 and the y-intercept is 8.

Relationship between the slopes of perpendicular lines:

  • The slopes of perpendicular lines are negative reciprocals of each other.

We can represent this with the equation m2 = -1 / m1, where:

  • m2 is the slope of the line we're trying to find,
  • and m1 is the slope of the line we're given (i.e., -2):

Finding m2:

Now, we can find m2 by substituting -2 for m1 in the perpendicular slope formula above:

m2 = -1 / -2

m2 = 1/2

Thus, the slope of the other line is m2.

Finding the y-intercept (b) of the other line and writing its equation:

Since the other line passes through (4, -2) and has a slope of 1/2, we can find its y-intercept (b) by substituting (4, -2) for (x, y) and 1/2 for m in the slope-intercept form:

-2 = 1/2(4) + b

(-2 = 2 + b) - 2

-4 = b

Therefore, y = 1/2x - 4 is the equation of the line that contains the point (4, -2) and is perpendicular to the line y = -2x + 8.

User Punit Rathore
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8.5k points