Answer:
cos(52°) = 18/x
x = 18·sec(52°)
Step-by-step explanation:
The mnemonic SOH CAH TOA reminds you that ...
Cos = Adjacent/Hypotenuse
In this geometry, that means ...
cos(52°) = 18/x
You can use the relation sec(x) = 1/cos(x) to rewrite this as ...
x = 18·sec(52°)
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You can also use the complementary angle and the complementary trig function.
sin(90° -52°) = 18/x
