Given that:
sec x+tan x=22/7.
Determine the value of:
csc x + cot x
sec x + tan x = 22/7
(1 + sinx)/cosx = 22/7
7(1 + sinx) = 22(cosx)
49(1 + 2sinx + sin^2(x)) = 484 cos^2(x)
add 484 sin^2(x) to both sides
49 + 98sin(x) + 533sin^2(x) = 484
533sin^2(x) + 98sin(x) - 435 = 0
sin(x) = [-98 ± sqrt(9604 + 927420)]/1066
note that 937024 = 968^2
sin(x) = [-98 + 968]/1066 = 870/1066 = 0.8161
or [-98 - 968]/1066 = 1066/1066 = 1
The arcsin(0.8161) = 0.954690764747344 radians
= 54.6997515601398 degrees
Plug into original equation: 3.14285714285714 = 22/7 check
The arcsin(1) = 1.5707963267949 radians
= 90 degrees
Plug into original equation: divide by zero; reject
x = 0.954690764747344 radians
csc x + cot x = 1.93333333333333 =
29/15In summary:
sec + tan = 22/7
csc + cot =
(22+7)/(22-7) Conclusion: there must have been a simpler solution
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Posted by Larry
on 2023-10-27 12:31:53 |