For each equation, determine whether it represents a direct variation, an inverse variation, or neither.
1 answer:
we know that in direct variation as x increase y also increases.
in indirect variation x decreases y increase and vice versa.
in part a we have x at top (numerator ) and y at denominator it mean indirect variation (as x increases y decreases).
to find k we know that for indirect variation xy=k
if we rewrite the equation x=9/y we get xy=9
which mean k=9 .
in part b we have 4xy=20 if we simplify this equation we get
so here if we rewrite in terms of x.
we get x=5/y which represents indirect variation.
and we know xy=k
we have xy=5 .so k=5
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Answer:
y = -2x - 2
Step-by-step explanation:
From the graph attached,
If the line 'l' passes through two points A(0, -1) and B(4, 1).
Rule for the rotation of any point (x, y), 90° clockwise about the origin is,
(x, y) → (y, -x)
By this rule,
A(0, -1) → A'(-1, 0)
B(4, 1) → B'(1, -4)
Let the equation of the line A'B' is,
y - y' = m(x - x')
where m = slope of the line A'B'
And (x', y') is a point lying on the line.
Slope of the line passing through A' and B' will be,
m =
m =
m = -2
Therefore, equation of the line passing through (-1, 0) and slope = -2,
y - 0 = (-2)(x + 1)
y = -2x - 2
So the equation of the line after rotation of lie 'l' by 90° clockwise will be,
y = -2x - 2
