The answer to your question is -12
Answer:
1) a) yes
b) no
c) a² - 39
(a)² - (sqrt(39))²
(a - sqrt(39))(a + sqrt(39))
This quadratic can be split into real factors, but not rational
sqrt(39) is a real number, but not rational
First we use product rule
y=x^2lnx
dy/dx = x^2 d/dx (lnx) + lnx d/dx (x^2)
dy/dx = x^2 (1/x) + lnx (2x)
dy/dx = x + 2xlnx
now taking second derivative:
d2y/dx2 = 1 + 2[x (1/x) + lnx (1)]
d2y/dx2 = 1 + 2[1+lnx]
1+2+2lnx
3+2lnx is the answer
The equation would be set up as 7-x or whatever the variable is