Try another version of this question
Evaluate `cos(tan^-1( 7/8))`, giving an exact answer.
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Box 1: Enter your answer as a number (like 5, -3, 2.2172) or as a calculation (like 5/3, 2^3, 5+4)
Enter DNE for Does Not Exist, oo for Infinity
Decimal values are not allowed
Trig functions (sin,cos,etc.) are not allowed
` (8sqrt(113))/113`