How to find all values of x where the tangent line is horizontal?

Your question is a rather general one.  However, it can be said that differentiating the given function of x with respect to x and setting the result = to 0, then solving for x, will produce all values of x where the t. l. is horizontal.

0=6x+2y+10 is equivalent to the simplified form: y= -3x - 5• parallel lines always have the same slope, different y intercept knowing this, we can say the slope, or m of the line parallel to y= -3x - 5 is -3.m= -3 hope this could !