Answer:
x^2-2x-4=0
Δ=2^2-4*1*(-4)
Δ=4+16=20
VΔ=2V5
x1= (2+2V5)/2=1+V5
the answer is D
Step-by-step explanation:
Number Line:
Closed Circles are used when signs are "≤" or "≥"
Open Circles are used when signs are "<" or ">"
The graph of x > -1 on a number line would be towards the right from -1 with open circle as the sign is ">"
Graph should look like this:
Answer:
The geometric mean of the measures of the line segments AD and DC is 60/13
Step-by-step explanation:
Geometric mean: BD² = AD×DC
BD = √(AD×DC)
hypotenuse/leg = leg/part
ΔADB: AC/12 = 12/AD
AC×AD = 12×12 = 144
AD = 144/AC
ΔBDC: AC/5 = 5/DC
AC×DC = 5×5 = 25
DC = 25/AC
BD = √[(144/AC)(25/AC)]
BD = (12×5)/AC
BD= 60/AC
Apply Pythagoras theorem in ΔABC
AC² = 12² + 5²
AC² = 144+ 25 = 169
AC = √169 = 13
BD = 60/13
The geometric mean of the measures of the line segments AD and DC is BD = 60/13
