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2 years ago

If y varies directly as x and y=3 when x=2 find y when x=8

Mathematics

2 answers:

goldfiish [28.3K]2 years ago

8 0

Answer:

y = 12 when x = 8

Step-by-step explanation:

This is a case of direct variation, and the pertinent equation is y = kx.

Substituting 2 for x and 3 for y, we get: 3 = 2k. Then k = 3/2 is the constant of proportionality.

Then y = (3/2)x.

When x = 8, y = (3/2)(8) = 12

satela [25.4K]2 years ago

6 0

Answer:

Step-by-step explanation:

x=2 was multiplied by 4 to get to x=8 so you multiply y=3 by 4 to make it y=12

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Read 2 more answers

zubka84 [21]

Answer:

See Explanation Below

Step-by-step explanation:

Given

$(sin x - cos x)^2 = sec^2x - tan^2x - 2sinx.cos x.$

Required

Prove

To start with; we open the bracket on the left hand side

$(sin x - cos x)^2 = (sin x - cos x)(sin x - cos x)$

$(sin x - cos x)^2 = (sin x )(sin x - cos x)- (cos x)(sin x - cos x)$

$(sin x - cos x)^2 = sin^2 x -sinx cos x - sin xcos x + cos^2 x$

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Reorder

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From trigonometry;

$sin^2x + cos^2x = 1$

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Also from trigonometry;

$sec^2x - tan^2x = 1$

So,

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2 years ago

If y varies directly as x and y=3 when x=2 find y when x=8​

If y varies directly as x and y=3 when x=2 find y when x=8