Question

read the text.
yodeling is a vocal technique once used by shepherds in the swiss alps. to yodel, you first have to find your normal, or \chest,\ voice, and your high, or \head,\ voice. yodeling involves switching between these two ranges of sound, or registers, and finding the break between them. to begin, make an \ah\ sound and move your voice from low to high, listening for the break. try to keep your voice relaxed, but dont allow the notes to flow smoothly. unlike other styles of singing, yodeling requires you to emphasize the break between notes.
which author’s purpose is suggested by the text?
to convince readers that yodeling is easy
to inform readers about the origins of yodeling
to teach readers how to yodel

Explanation:

The text provides steps on how to yodel (finding chest/head voice, switching registers, making "ah" sound, etc.), not to convince it's easy (no persuasive language) or just inform about origins (only a brief mention of origin, main content is instructions). So the purpose is to teach readers how to yodel.

Answer:

to teach readers how to yodel