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3 years ago

11

A class has 24 boys and 16 girls. on a test the class mean was 75. the mean of the girls' score was 72. what was the mean of the

boys' scores?

2 answers:

Mice21 [21]3 years ago

6 0

jhnkjhn jnjhvgfhjvb fcgvgfhcv fcgh jfgch jklk

ArbitrLikvidat [17]3 years ago

3 0

24+16=40
40*75=3000
16*72=1152
3000-1152=1848
1848/24=77

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Verify the identitiy:

Advocard [28]

Answer:

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Step-by-step explanation:

To verify the identity:

sinx/1-cosx = cscx + cotx

we will follow the steps below;

We will take just the left-hand side and work it out to see if it is equal to the right-hand side

sinx/1-cosx

Multiply the numerator and denominator by 1 + cosx

That is;

$\frac{sinx}{1-cos x}$ = $\frac{sinx(1+cosx)}{(1-cosx)(1+cosx)}$

open the parenthesis on the right-hand side of the equation at the numerator and the denominator

sinx(1+cosx) = sinx + sinx cosx

(1-cosx)(1+cosx) = 1 - cos²x

Hence

$\frac{sinx(1+cosx)}{(1-cosx)(1+cosx)}$ = $\frac{sinx + sinx cosx}{1-cos^{2}x }$

But 1- cos²x = sin²x

Hence we will replace 1- cos²x by sin²x

$\frac{sinx}{1-cos x}$ = $\frac{sinx(1+cosx)}{(1-cosx)(1+cosx)}$ = $\frac{sinx + sinx cosx}{1-cos^{2}x }$ = $\frac{sinx+sinxcosx}{sin^{2}x }$

= $\frac{sinx}{sin^{2}x }$ + $\frac{sinxcosx}{sin^{2}x }$

= $\frac{1}{sinx}$ + $\frac{cosx}{sinx}$

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$\frac{sinx}{1-cos x}$ = $cosecx$ + $cot x$

Note that;

$\frac{1}{sinx}$ = $cosecx$

$\frac{cosx}{sinx}$ = $cot x$

6 0

3 years ago

Anybody...Help!!!!!!!!!!!

Sloan [31]

Simple...

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lys-0071 [83]

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Let k is the ratio between two variables or y = kx

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3 years ago

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Rashid [163]

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2 years ago

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