MAT - Paper 2007 - Q1D
Flashcards
Shortest distance between two circles
Does the line $y = \frac{3}{4}x$ go through the circle
\[(x - 1)^2 + (y - 1)^2 = 1\]
?
No way Jose.
These are the circles
\[(x - 1)^2 + (y - 1)^2\]
and
\[(x - 5)^2 + (y - 4)^2 = 4\]
What is the vector for moving from the little circle to the big circle?
These are the circles
\[\left(\begin{matrix} 4 \\\\ 3 \end{matrix}\right)\]
If the vector for moving between the centre of each of the two circles (Dad) is
\[\left(\begin{matrix} 4 \\\\ 3 \end{matrix}\right)\]
(magnitude $5$), then what fraction of the journey is taken up by moving out of the first circle and up to the outside of the second circle?
If the vector for moving between the centre of each of the two circles (Dad) is
\[\frac{3}{5}\]
When a coordinate geometry problem is getting tricky and you’re not allowed a calculator (i.e. the quadratic isn’t clearly factorisable or you’re having to substitute $y = \frac{3}{4}x + \frac{1}{4}$) then what could be an alternate way of tackling the problem?
Using vectors.