Answer:
The domain of function 
is set of all real numbers.
Domain: (-∞,∞)
Step-by-step explanation:
Given:
the domain of both the above functions is all real number.
To find domain of :
Substituting functions 
and 
to find
The product can be written as difference of squares. ![[a^2-b^2=(a+b)(a-b)]](https://tex.z-dn.net/?f=%5Ba%5E2-b%5E2%3D%28a%2Bb%29%28a-b%29%5D)
∴ 
The degree of the function is 2 as the exponent of leading term 
is 2. Thus its a quadratic equation.
For any quadratic equation the domain is set of all real numbers.
So Domain of is (-∞,∞)
Answer:
look at the picture above
Answer:
22
Step-by-step explanation:
Given
2t + 4s ( substitute t = 5, s = 3 into the expression )
= 2(5) + 4(3)
= 10 + 12
= 22
Answer:
90% confidence interval for the mean is between a lower limit of 3.08 days and an upper limit of 3.18 days.
Step-by-step explanation:
Confidence interval is given as mean +/- margin of error (E)
mean = 3.13 days
sd = 0.48 day
n = 250
degree of freedom = n-1 = 250-1 = 249
confidence level (C) = 90% = 0.9
significance level = 1 - C = 1 - 0.9 = 0.1 = 10%
critical value (t) corresponding to 249 degrees of freedom and 10% significance level is 1.65153
E = t×sd/√n = 1.65153×0.48/√250 = 0.05 day
Lower limit of mean = mean - E = 3.13 - 0.05 = 3.08 days
Upper limit of mean = mean + E = 3.13 + 0.05 = 3.18 days
90% confidence interval is (3.08, 3.18)
