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Write the general solution to y = arcsin (0.6428).

40°±360°k
140°±360°k
220°±360°k
320°±360°k

How do I find the right answer? I am like seriously stuck. I need help please.

• inverse trig HELP PLEASE!! -

set your calculator to degrees (the DRG key)

enter:
2ndF
sin
.6428
=

you should get 40.00...

since sinØ has a period of 360° , adding or subtracting multiples of 360° will produce the same answer

so 40° ± 360k would be the general solution

you might check with some arbitrary value of k
say k = 5
then 40 + 5(360) = 1840
sin 1840° = .64278 , close enough!

(on some calculators you have to enter the argument first,
e.g.
.6428
2ndF
sin

you will have to test your device.

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