Answer:-2 and 2
Step-by-step explanation:
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
Answer:
<em>4.52secs</em>
Step-by-step explanation:
Given the height of a falling object expressed as;
d=3t+5t^2
If the object travel 84 feet, we are to find the time t it takes to travel. On substituting;
84 = 3t+5t^2
3t+5t^2 - 84 = 0
t = -5±√25-4(3)(-84)/2(3)
t = -5±√25+1008/6
t = -5±32.14/6
t = -5+32.14/6
t = 27.14/6
<em>t = 4.52 secs</em>
<em>Hence it will take 4.52secs for the object to travel 84feet</em>
When simplified the answer is -2n^3+13
