Writing Equations of lines

y = -5/3x+8

Step-by-step explanation:

Equation: y=mx+b

You find the slope (m) by calculating the distance between the two points. For the y axis, 3 is -5 away from 8. For the x axis, 3 is 3 away from 0. You then devide y by x, which gives you -5/3.

To get the y intercept (b), you just look at the graph, where it's at 8.

God luck!

y = -5/3x + 8

Step-by-step explanation:

Points on the graph: (0, 8) and (3, 3)

Slope:

m=(y2-y1)/(x2-x1)

m=(3-8)/(3-0)

m= (-5)/3

m= -5/3

Slope-intercept:

y - y1 = m(x - x1)

y - 8 = -5/3(x - 0)

y - 8 = -5/3x

y = -5/3x + 8

4√2/7

Step-by-step explanation:

Suppose cos(x)=-1/3, where pi/2≤x≤ pi

tan(2x) = sin(2x)/cos(2x)

Since sin2x = 2sinx cosx

cos 2x = 2cos²x-1

Substitute

tan(2x) = 2sinx cosx/ 2cos²x-1

Given cosx = -1/3

adjacent = -1

hyp = 3

opp = √3²-(-1)²

opp = √9-1

opp = √8

sinx = opp/hyp

sinx = √8/3

tan(2x) = 2sinx cosx/ 2cos²x-1

tan(2x) = 2(√8/3)(-1/3)/ 2(-1/3)²-1

tan2x= (-2√8/9 )÷ (2/9 - 1)

tan2x = -4√2/9 * 9/-7

tan 2x = 4√2/7