Question

Find the 2 points where the curve x^2+xy+y^2=7 crosses the x-axis, and show that the tangents to the curve at these points are parallel. what is the common slope of these tangents?

No clue. Help is much appreciated :)

Answer 1

wherever the curve crosses x-axis, you cn use the condition y=0

Answer 2

@him1618 then what?

Answer 3

cn u tell me the eqn now?

Answer 4

x^2=7?

Answer 5

put y=0
in ur eqn
u get
x^2 = 7

Answer 6

solve it for

Answer 7

x=7^1/2?

Answer 8

+ root 7 and - root 7

Answer 9

that's it?

Answer 10

so the points are (+root7, 0) and (-root7, 0)

Answer 11

yes, that's it?

Answer 12

now u need to find the slopes at these two points

Answer 13

can u find y' from ur eqn?

Answer 14

thank you :)