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Anestetic [448]

3 years ago

14

Diana invested $3000 in a savings account for 3 years. She earned $450 in interest over that time period. What interest rate did

she earn?

2 answers:

Aleks04 [339]3 years ago

7 0

So she invested $3000. 450 of 3000 would be 0.15 which is 15%. So in one year, interest rate would be 15% divided by 3 years = 5 %
Best of luck!

REY [17]3 years ago

3 0

formula I=Prt 450= (3000) r (3) 450=9000r 450/9000=9000r 0.05=r

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slamgirl [31]

If you're using the app, try seeing this answer through your browser: brainly.com/question/2927231

————————

You can actually use either the product rule or the chain rule for this one. Observe:

• Method I:

y = cos² x

y = cos x · cos x

Differentiate it by applying the product rule:

$\mathsf{\dfrac{dy}{dx}=\dfrac{d}{dx}(cos\,x\cdot cos\,x)}\\\\\\
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—————

• Method II:

You can also treat y as a composite function:

$\left\{\!
\begin{array}{l}
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and then you get the same answer:

$\therefore~~\boxed{\begin{array}{c}\mathsf{\dfrac{dy}{dx}=-2\,sin\,x\cdot cos\,x}\end{array}}\qquad\quad\checkmark$

I hope this helps. =)

Tags: <em>derivative chain rule product rule composite function trigonometric trig squared cosine cos differential integral calculus</em>

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Read 2 more answers

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