http://screencast.com/t/whGrG2wQ

Help in this, without using Log ? :)

Question

http://screencast.com/t/whGrG2wQ

Help in this, without using Log ? :)

anonymous · Answer

@satellite73 @ParthKohli @UnkleRhaukus

unklerhaukus · Answer

$$y(x)=ka^x$$
what is y when x=0

unklerhaukus · Answer

ie the y-intercept

callisto · Answer

(i)
for exponential graph y= a^x , it passes the point (0,1)
Compare that point to the graph, you can get the value of k
The point on the graph is (0, 0.5) 
So, k =0.5

(ii)
Choose a point from the graph, and put the value into the equation y=0.5a^x
you can solve a ... I think

anonymous · Answer

k = 2, you are wrong...?

unklerhaukus · Answer

$$k=\frac 12$$

callisto · Answer

My bad :|

anonymous · Answer

it is correct sorry @Callisto and i got a = 3 ;) thanks

unklerhaukus · Answer

$$y(x)=ka^x$$
$$y(1)=ka^1=ka\qquad=   \frac32 (\text{from the graph})$$

callisto · Answer

If the equation is y=2(1.5)^x http://www.wolframalpha.com/input/?i=y%3D+2%281.5%29%5Ex If the equation is y=0.5(3)^x http://www.wolframalpha.com/input/?i=y%3D+0.5%283%29%5Ex

callisto · Answer

I still can't work out why I was wrong... stupid me...