Answer:
cosA = √(21/25)
Step-by-step explanation:
We know
sin²(A) + cos²(A) = 1
Next, we know that sin(A) = 2/5. Plugging that into our equation, we get
(2/5)² + cos²A = 1
4/25 + cos²A = 1
subtract 4/25 from both sides to isolate cos²A
cos²A = 1 - 4/25 = 25/25-4/25 = 21/25
square root both sides to get
cosA = √(21/25)
We do not include -√(21/25) in our possible answer for cosA because this is in quadrant 1, so cosA must be positive.
Answer:
a=108
Step-by-step explanation:
180x3=540
540/5=108
a=108˚
Answer:
Step-by-step explanation:
<u>The line with points (1,2) and (-1,-8). Work out its equation.</u>
<u>The slope is:</u>
- m = (-8 - 2)/(-1 - 1) = -10/-2 = 5
<u>To find the y intercept, substitute x and y-xoordinates of point (1,2):</u>
- 2 = 5(1) + b
- b = 2 - 5
- b = -3
<u>The line is:</u>
<u>Point (x, 17), substitute y-coordinate and solve for x</u>
- 17 = 5x - 3
- 5x = 17 + 3
- 5x = 20
- x = 20/5
- x = 4
Answer:
a=-6
Step-by-step explanation:
4= 6/a + 5
Subtract 5 from each side
4-5= 6/a + 5 -5
-1 = 6/a
Multiply by a on each side
-1*a = 6/a *a
-a =6
Multiply by -1
a= -6
