3 16. If 270º < AS 360° and cos(A)= 3/4 then determine the exact values of sin (A) and tan ( A)

Mathematics

1 answer:

suter [353]3 years ago

4 0

Answer:

${ \boxed{ \tt{trig \: identity : { \bf{ { \cos}^{2} A + { \sin }^{2} A = 1}}}}} \\ \therefore \: { \green{ \tt{ \sin A = \sqrt{1 - { \cos }^{2}A } }}} \\ \sin A = \sqrt{1 - {( \frac{3}{4}) }^{2} } \\ \sin A = \frac{ \sqrt{7} }{4} = 0.661 \\ \\ { \green{ \tt{ \tan A = \frac{ \sin A }{ \cos A} }}} \\ \tan(A ) = \frac{ \frac{ \sqrt{7} }{4} }{ \frac{3}{4} } = \frac{ \sqrt{7} }{3} = 0.882 \\ \\ { \underline{ \blue{ \tt{ becker \: jnr}}}}$

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What is the value of the correlation coefficient r of the data set?

enyata [817]

The correct option will be: C) 0.84

Explanation

Formula for Correlation coefficient :

$r= \frac{n(\Sigma xy)-(\Sigma x)(\Sigma y)}{\sqrt{[n\Sigma x^2-(\Sigma x)^2][n\Sigma y^2-(\Sigma y)^2]}}$

First, for each point(x, y), we need to calculate x², y² and xy .

Then, we will find sum all x, y, x², y² and xy, which gives us Σx, Σy, Σx², ∑y² and Σxy

(Please refer to the attached image for the table )

Here we got, ∑x = 44 , ∑y = 183 , ∑x² = 362 , ∑y² = 6575 and ∑xy = 1480

'n' is the total number of data set, which is 7 here.

So, plugging those values into the above formula..........

$r= \frac{n(\Sigma xy)-(\Sigma x)(\Sigma y)}{\sqrt{[n\Sigma x^2-(\Sigma x)^2][n\Sigma y^2-(\Sigma y)^2]}}\\ \\ r=\frac{7(1480)-(44)(183)}{\sqrt{[7(362)-(44)^2][7(6575)-(183)^2]}}\\ \\ r=\frac{10360-8052}{\sqrt{(598)(12536)}}\\ \\ r=\frac{2308}{\sqrt{7496528}}\\ \\ r=0.84$