Hint #1:
Identify which line segments on the diagram are equal to sin(beta), cos(beta), and the quantity we want, sin(alpha+beta).
Hint #2:
Can you think of a ratio that equals sin(alpha) and one that equals cos(alpha)?
Hint #3:
What is angle CDF equal to ?... are there any similar triangles in the diagram? Which ones?
Hint#4:
See if you can determine values for the lengths FC, FD, EC, and OE in terms of the sines and cosines of alpha and beta.
Subscribe to:
Post Comments (Atom)
10 comments:
I was wondering if anyone is using FC and OE in their proof? I have proved the law, but I didn't use FC and OE. Did Mr. Kerai give that to us for the proof, or was he just giving that to us so we get all the information there and then sift through what we might need? Just curious.
Victoria, I think you have a good idea of the purpose of finding expressions for FC and OE. It is possible to not need those lengths. Let's see what other members of your group have to say.
i was thinking find CE and DF and using those to fing DG (cause they equal it) but i can't figure out how
Jack. Look at CE and DF. Can you find equations for the sin and cos of alpha that have these lengths in them? (Using the two similar triangles on the right.)Once you do this, you can replace some of the lengths with what you already know, or at least you should know, substitute that to find GE, and voila, you have the formula. Do you follow?
i don't think i used OE or FC. i substituted the cosines and sines of beta to get FD and FG, which adds up to DG. is that what you did victoria?
Virginai, that is what I did.
GE?
ill just have to see in class, i think i kinda have the idea but cant really formulate my ideas in formulas and whatnot, Mr. Kerai, will we have time to discuss in class?
Sorry Jack. I meant DG.
Victoria and Virginia have the right idea. Some of the lengths are not particularly useful and other ratios are. Bottom line is, as Victoria suggest, I was trying to get you to write out all you know and then "sift" out the necessary stuff from there.
Post a Comment