Substitute each x and the respecting y to the equation
A)
145 - 5d
5d = 145, set equal
29 days to lay all the track
b)
5*19 = 95
145-95 = 50
After 19 days, they have 50 miles to go.
<span>is is 42 ok but try to see why and study =)</span>
Answer:
•cos(s+t) = cos(s)cos(t) - sin(s)sin(t) = (-⅖).(-⅗) - (√21 /5).(⅘) = +6/25 - 4√21 /25 = (6-4√21)/25
•cos(s-t) = cos(s)cos(t) + sin(s)sin(t) = (-⅖).(-⅗) + (√21 /5).(⅘) = +6/25 + 4√21 /25 = (6+4√21)/25
cos(t) = ±√(1 - sin²(t)) → -√(1 - sin²(t)) = -√(1 - (⅘)²) = -⅗
sin(s) = ±√(1 - cos²(s)) → +√(1- cos²(s)) = +√(1 - (-⅖)²) = √21 /5
Hello,
-2<1 ==> f(x)=3x²-1 =>f(-2)=3*(-2)²-1=3*4-1=12-1=11
