X²+y²-2y=7 using the formula that links Cartesian to Polar coordinates x=rcosθ and y=r sin θ substituting into our expression we get: (r cos θ)²+(r sin θ)²-2rsinθ=7 expanding the brackets we obtain: r²cos²θ+r²sin²θ=7+2rsinθ r²(cos²θ+sin²θ)=7+2rsinθ using trigonometric identity: cos²θ+sin²θ=1 thus r²=2rsinθ+7 Answer: r²=2rsinθ+7
She can purchase around 3 T-shirts because out of the $200, the ticket is $87.96 which leaves us left with $112.04. Each T-shirt is 30$. You just divide $112.04 by $30.
