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Answer:
Wasim has enough money.
Step-by-step explanation:
1. find the area of the garden path:
600 cm x 120 cm = 72,000 sq. cm
2. find the area of each stone:
it is a square of 30 cm by 30 cm, so:
30 cm x 30 cm = 900 sq. cm
3. find how many stones can fit in the path:
72,000 / 900 = 80 stones
4. multiply that by the price of each stone:
80 stones x $2.50 = $200
Wasim's budget is $220 and the stones will only cost $200, so it is within the budget
By converting into parametric equations,
<span>{<span><span>x<span>(θ)</span>=r<span>(θ)</span><span>cosθ</span>=<span>cos2</span>θ<span>cosθ</span></span><span>y<span>(θ)</span>=r<span>(θ)</span><span>sinθ</span>=<span>cos2</span>θ<span>sinθ</span></span></span></span>
By Product Rule,
<span>x'<span>(θ)</span>=−<span>sin2</span>θ<span>cosθ</span>−<span>cos2</span>θ<span>sinθ</span></span>
<span>x'<span>(<span>π2</span>)</span>=−<span>sin<span>(π)</span></span><span>cos<span>(<span>π2</span>)</span></span>−<span>cos<span>(π)</span></span><span>sin<span>(<span>π2</span>)</span></span>=1</span>
<span>y'<span>(θ)</span>=−<span>sin2</span>θ<span>sinθ</span>+<span>cos2</span>θ<span>cosθ</span></span>
<span>y'<span>(<span>π2</span>)</span>=−<span>sin<span>(π)</span></span><span>sin<span>(<span>π2</span>)</span></span>+<span>cos<span>(π)</span></span><span>cos<span>(<span>π2</span>)</span></span>=0</span>
So, the slope m of the curve can be found by
<span>m=<span><span>dy</span><span>dx</span></span><span>∣<span>θ=<span>π2</span></span></span>=<span><span>y'<span>(<span>π2</span>)</span></span><span>x'<span>(<span>π2</span>)</span></span></span>=<span>01</span>=0</span>
I hope that this was helpful.
