Figure 1
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The circle C, with centre (a, b) and radius 5, touches the x-axis at (4, 0), as shown in Fig. 1.
- Write down the value of a and the value of b. [1]
- Find a cartesian equation of C. [2]
A tangent to the circle, drawn from the point P(8, 17), touches the circle at T.
- Find, to 3 significant figures, the length of PT. [3]