<span>Being able to estimate your answer is a very useful skill. ... When decimals are involved, it's very easy to put the decimal point in the wrong place, and ... round all numbers to the same place value—this makes adding or subtracting a bit easier.</span>
Answer:
False, true, true, false, false
Step-by-step explanation:
Remember that the vertex form of a parabola or quadratic equation is:
y=a(x-h)^2+k, where (h,k) is the "vertex" which is the maximum or minimum point of the parabola (and a is half the acceleration of the of the function, but that is maybe too much :P)
In this case we are given that the vertex is (1,1) so we have:
y=a(x-1)^2+1, and then we are told that there is a point (0,-3) so we can say:
-3=a(0-1)^2+1
-3=a+1
-4=a so our complete equation in vertex form is:
y=-4(x-1)^2+1
Now you wish to know where the x-intercepts are. x-intercepts are when the graph touches the x-axis, ie, when y=0 so
0=-4(x-1)^2+1 add 4(x-1)^2 to both sides
4(x-1)^2=1 divide both sides by 4
(x-1)^2=1/4 take the square root of both sides
x-1=±√(1/4) which is equal to
x-1=±1/2 add 1 to both sides
x=1±1/2
So x=0.5 and 1.5, thus the x-intercept points are:
(0.5, 0) and (1.5, 0) or if you like fractions:
(1/2, 0) and (3/2, 0) :P
B) 12.75
Just add them all together
10+15+14+8+18+11+12+12+10+10+17+16=153
The devide the anser by the ammount of numbers you added together
153÷12=12.75
Time:logs=time:logs
time/logs=time/logs
4hours:6logs=18hours:xlogs
4hours/6logs=18hours/xlogs
4/6=18/x
6/4=18/x
x=27
pick B,C,E
