Answer:
Step-by-step explanation:
To prove the straight line is tangent to the circle:
(1)
substitute x = 2y + 5 into x² + y² = 5
x² + y² = 5
(2y + 5)² + y² = 5
4y² + 20y + 25 + y² = 5
5y² + 20y + 20 = 0
y² + 4y + 4 = 0
(2)
discriminant of y² + 4y + 4 = 0 has to be equals to 0
D = 4² - 4(1)(4)
D = 0
∴ Proven
–9x + 3y = 12
infinitely many solutions
no solution
(0, –2)
(–2, 4)
Answer:
11
Step-by-step explanation:
Use PEMDAS
level after I day was 5380 bacteria per cubic centimeter.
Answer: the function N(t) to estimate the level of contamination in the lake is:
N(t) = -1110 ln(t) - 230t + 1110 ln(I) + 230I + 5380
Step-by-step explanation: ∫ dN/dt dt = ∫ (-1110/t² -230) dt
N(t) = -1110 ln(t) - 230t + C
N(I) = -1110 ln(I) - 230I + C = 5380
C = 1110 ln(I) + 230I + 5380