PLEASE HELP

In the proof of the Law of Cosines, the equation c^2=h^2+(b-x)^2was created using the Pythagorean theorem. Which equation is a result of expanding (b-x)^2?

A.c^2=h^2+b^2-x^2
B.c^2=h^2+b^2-2bx+x^2
C. c^2=h^2+b^2+x^2
not D

Two construction workers, Tyrone and Diego, are standing 15 yards apart, looking up at a piano hanging between the two men from a crane. Tyrone is staring at the piano with an angle of elevation of 65°, and Diego is looking up with an angle of elevation of 77°. What is the distance between Tyrone and the piano? Round the answer to the nearest tenth.

9.0 yd
16.1 yd
22.1 yd
23.7 yd

Answer :

Answer:

Q1 B

Q2 23.7yd

Step-by-step explanation:

Solution of Q2 is in the picture

${teks-lihat-gambar} ernest725
whitneytr12

Answer:

a) [tex]c^{2}=h^{2}+(b-x)^{2}=h^{2}+b^{2}-2bx+x^{2}[/tex]

Therefore letter B is the correct answer.

b) TP = 23.7 yards  

Step-by-step explanation:

a) We can rewrite [tex](b-x)^{2}[/tex] as (b-x)(b-x), so we have a product of two binomials. We can use the FOIL method to multiply it:

[tex](b-x)(b-x)=b^{2}-bx-bx+x^{2}=b^{2}-2bx+x^{2}[/tex]

so the the Law of Cosines equation will be write as:

[tex]c^{2}=h^{2}+(b-x)^{2}=h^{2}+b^{2}-2bx+x^{2}[/tex]

Therefore letter B is the correct answer.

b) Here we can use the Law of sines.

  • TP is the distance between Tyrone and the piano
  • DP is the distance between Diego and the piano
  • TD is the distance between Diego and Tyrone.

∠A angle between TD and TP = 65°

∠B angle between TD and DP = 77°

∠C angle between TP and DP = 180° - 77° - 65° = 38°

The equation is:

[tex]\frac{TP}{sin(B)}=\frac{TD}{sin(C)}[/tex]

[tex]\frac{TP}{sin(77)}=\frac{15}{sin(38)}[/tex]    

Solving it for TP, we have:

[tex]TP=sin(77)\frac{15}{sin(38)}=23.7 yards[/tex]  

I hope it helps you!  

Other Questions