Which of the following describes the rigid transformation in the function shown below? y+5= -2(x-1)^2 A. The graph is shifted 5 units down. B. The graph is shifted 1 unit left. C. The graph is reflected across the x-axis. D. The graph is stretched vertically by a factor of 2. ***idk please explain? thanks ;)
do u understand this?
i do, but more than one answer applies...so could there be more to the instructions?
no :(
well the +5 on the left side gets subtracted from both sides to get y = -2(x-1)^2 - 5 so that means choice A is the answer BUT the negative on -2 (outside the parenthesis) implies that the graph is reflected over the x-axis, so choice C is also the answer
wait what??? so they are BOTH the answer???
yeah that's exactly what I was thinking...they both can't be the answer
which would be the most logical answer though? Answer A?
well, last time it was reflected when it was like this kinda: y= -3x^2+1
and this one would become -2x+2 so that would reflect also?
and k=-5 so it is shifted 5 units down.. so idk? they both seem correct... but i can only choose one?
yeah that's why I'm asking if there's more
no that's all there is to the question
hmm it's like they're doing this to mess with you lol
does it mean anything when it says RIGID TRANSFORMATION?
hahaa ikr?
well they're all rigid transformations
oh okay, so which one seems more logical to u tho?? i have to choose one now :/ and if it's wrong i can talk to my teacher :/
oh wait, scaling isn't a rigid transformation
so we can at least eliminate D
it's either A or C
B is incorrect because it's going the wrong way
okay, which seems like the definite definite answer (and yes i meant to say definite twice teehehehe) :P
? sorry that was a question haha
hmm i'll go with C...it seems like we have to manipulate the equation a bit to get A
okay =) ill just cross my fingers that C is the answer haha :) and i can always explain to my teacher later :)
hahaa thanks for the help!! :D hope C is right!! :)
me too
I'm not seeing the reflection across the x - axis, I think the answer is A.
reflection across the x - axis implies that a given x value would result in two y values one above and one below the x - axis, but this is not the case
what do you mean? can u pls explain some more?
@tjones89 :)
for a function to reflect about an axis, you should be able to plug in two different x values and get the same value for y, for example, y = x^2 if I plug in a -1 or a 1 I get the same y value
you're thinking of a reflection across the y axis (not x axis)
right but the same idea applies, if I want reflection about the x axis, I need to be able to use one x value to get two y values, one above and one below. This function does not have that property
no function has that property...i think they want to know what transformations are done to the parent function y = x^2 to get y+5= -2(x-1)^2
wait so my answer is C then still?
but a reflection about the x axis implies that I should be able to fold the graph at the x axis and have the top and bottom parts line up, graphing this function shows that this is not the case
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