Answer: Todd used 27 black tiles.
Step-by-step explanation:
Let x represent the number of black tiles that Todd used.
Todd uses 21 white tiles & some black tiles to make a mosaic. This means that the total number of white and black tiles that Todd used is 21 + x
Each tile has an area of 3 square centimeters. This means that the total area covered by the white tiles is
21 × 3 = 63 square centimeters
Also, the total area covered by the black tiles is
3 × x = 3x square centimeters
The mosaic has a total area of 144 square centimeters. This means that
3x + 63 = 144
3x = 144 - 63
3x = 81
x = 81/3 = 27
Hey!
You can make a proportion:
Cross multiply
Divide by 2
<em>5 pounds would cost $10.50</em>
Good luck and hope this helps! :)
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.
What is this type of math called please and what year/grade if you don’t mind me asking so I can be prepared
