By converting into parametric equations,
<span><span>x(θ)=r(θ)cosθ=cos2θ<span>cosθ
</span></span><span>y(θ)=r(θ)sinθ=cos2θsinθ</span></span>
By Product Rule,
<span>x'(θ)=−sin2θcosθ−cos2θsinθ</span>
<span>x'<span>(π/2)</span>=−<span>sin(π)</span><span>cos<span>(π/2)</span></span>−<span>cos(π)</span><span>sin<span>(π/2)</span></span>=1</span>
<span>y'(θ)=−sin2θsinθ+cos2θcosθ</span>
<span>y'<span>(π/2)</span>=−<span>sin(π)</span><span>sin<span>(π/2)</span></span>+<span>cos(π)</span><span>cos<span>(π/2)</span></span>=0</span>
So, the slope m of the curve can be found by
<span>m=<span>dy/dx</span><span>∣<span>θ=<span>π2
</span></span></span>= <span><span>y'<span>(π/2)/</span></span><span>x'<span>(π/2)
</span></span></span></span>=0/1
=0
I hope my answer has come to your help. Thank you for posting your question here in Brainly.
Answer:
Step-by-step explanation:
The answer is $11.55 for the week.
1) Since 1 watt is 0.001 kilowatts, 1500 watts is 1.5 kilowatts.
2) Multiply that by 7 for the week and that equals 10.5.
3) It takes her 10 minutes each day, so it takes 70 minutes per week, that is also 1.1 hours.
4) Multiply 10.5 kilowatts by 1.1 hours and you get 11.55.
5) The answer is $11.55 per week to dry Lisa's hair.
THE ANSWER IS 1 23/100
(there is a space between the one and 23)
