CoHF WILL BE 704 PAGES LONG (x)

richardegansey

*Follow*

CoHF WILL BE 704 PAGES LONG (x)

richardegansey

taiseuse

Blue Book page 704 #17

To get this one right, you have to either know the graph translation rules, or be able to derive them on the fly. I’d recommend knowing them. :)

*f*(*x*)+1 ⇒ (graph moves UP one)*f*(*x*)-1 ⇒ (graph moves DOWN one)*f*(*x*+1) ⇒ (graph moves LEFT one)*f*(*x-*1) ⇒ (graph moves RIGHT one)

So *f*(*x* + 2) is going to move the original graph 2 spaces to the LEFT. The only choice that does that is (C).

pwnthesat

mrluggs said:

BB 6 #18 page 704. Can you please solve/explain?

I tried to color code the degree measures in the diagram so that this was easier to follow. The black numbers are just what you’re given: ∠*ABC* measures 30° and ∠*BDE* measures 50°.

You’re also told that *AB* = *BC*, and that *DE* = *EF* = *FD*, which means the big triangle is isosceles, and the smaller, inner triangle is equilateral. The red numbers reflect the fact that ∠*A* and ∠*C* must be equal and add up to 150° since ∠*B* is 30°, and all the angles in an equilateral triangle are 60°.

From here, you can fill in more angles. To get ∠*ADF*, you recognize that *AB* is a straight segment, so its measure is 180°. You’ve already got a 50° and a 60° angle there, so ∠*ADF* must be 70° to make 180°. Then you have 2 of the 3 angles in triangle *ADF*, so you can solve for ∠*DFA*, which is 35°. The green numbers represent these last steps.

[For a bit more practice with triangles, read this post.]

pwnthesat