Select the correct answer from each drop-down menu.

A student begins a proof of the law of cosines. His work is shown.

Triangle XYZ has side XY labeled z, side YZ labeled x, and side ZX labeled y. Point A is shown on side ZX. Segment AY is drawn that makes a right angle with side ZX. Segment AX is labeled z times cosine of X.

The next step in the proof is to write an expression for the length of side A in terms of
A. y, z, and X
B. y, z, and Y
C. x, z, and Z.

Then the student should write an expression for the length of side AY in terms of
A. z and Y
B. z and X
C. x and Z

Next he can use the
A. Pythagorean theorem
B. tangent function
C. law of sines
to relate x, y, z and
A. X
B. Y
C. Z.

1 answer

First Drop-down Menu: B. y, z, and Y

Second Drop-down Menu: A. z and Y

Third Drop-down Menu: A. Pythagorean theorem - A. X