Work out the equation of the tangent to a circle of centre [0,0] at the point [4,3]

We know that: (1) the radius of the circle to the point [4,3] is perpendicular to the tangent line, (2) if two lines are perpendicular, their gradients are negative reciprocals of each other, and (3) the formula for a straight line is y = mx + c. The radius gradient is equal to 3/4, so the tangent gradient is -4/3. Substituting m, y and x at [4,3] into the straight line formula gives c as 25/3. Therefore, the equation of this tangent line is y = (-4/3)x + (25/3).

Answered by Jamie S. Maths tutor

6530 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve simultaneously 2x+3y=8, 3x+2y=7 to calculate values of x and y.


Solve this simultaneous equation using the process of elimination: -6x - 2y = 14 3x - 2y = 5


There are only 7 blue pens, 4 green pens and 6 red pens in a box. One pen is taken at random from the box. Write down the probability that this pen is blue.


How do I solve a simultaneous equation?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences