10,000,000+2,000,000+400,000+30,000
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
Answer:
y4.5
Step-by-step explanation:
Answer:
You didn't give the expression whose zero you want to find. From the options you wrote, the expression has two zeros, this means it is a quadratic expression.
I will however explain how to find the zero of a quadratic expression.
Step-by-step explanation:
An expression is called quadratic, if the highest degree of the variable is 2, no more, no less. It is of the form: ax² + bx + c, where a, b, and c are constants.
The zeros of a quadratic expression are the values that make the expression vanish, that is equal to zero.
Example: Find the zeros of 2x² - 6x + 4
First, equate the expression to zero
2x² - 6x + 4 = 0
Next, solve for x
2x² - 2x - 4x + 4 = 0
2x(x - 1) - 4(x - 1) = 0
(2x - 4)(x - 1) = 0
(2x - 4) = 0
Or
(x - 1) = 0
2x - 4 = 0
2x = 4
=> x = 4/2 = 2
Or
x - 1 = 0
x = 1
Therefore, the zeros of the polynomial are 1 and 2.
