You have to check f(1) in each one to see if it's right and for f(4)
Answer:
157 in
Step-by-step explanation:
2x3.14x25 = 157 in
Square root means 46225^1/2 so the answer is 65
Circumference of circle = pi*diameter = 13pi cm
Area is pi*d^2/4 = pi*13^2/4 = 42.25pi cm^2.
Answer:
a). 59.049°C
b). 2.1179 seconds
Step-by-step explanation:
Expression representing the final temperature after decrease in temperature of the metal from 100°C to T°C is,
T = 
where x = duration of cooling
a). Temperature when x = 5 seconds
T = 100(0.9)⁵
= 59.049
≈ 59.049°C
b). If the temperature of the metal decreases from 100°C to 80°C
Which means for T = 80°C we have to calculate the duration of cooling 'x' seconds
80 = 
0.8 = 
By taking log on both the sides
log(0.8) =log[
]
-0.09691 = x[log(0.9)]
-0.09691 = -0.045757x
x = 
x = 2.1179
x ≈ 2.1179 seconds