The curve y = √8x + 1 and the tangent at the point P(3,5) on the curve. This tangent meets the y-axis. Find the equation of the tangent at P.
Can anyone pls tell me how to solve this? I've tried many times and I got wrong answer :S The answer is supposed to be 4x-5y+13=0 but i got y=4x+7
I finally got the answer. I didn't read the question carefully. The point is given (3,5). To find the gradient of the tangent. The x = 3 not 0. I didn't know where the 0 came from. hehe. The gradient is 4/5 not 4. Then I can solve using this equation y = mx + c
5 = 4/5(3) + c
so c = 13/5 so. the equation of the tangent is y = 4/5x +13/5. Which means 5y=4x+13.