Mathc initiation/a0075
Calculons la dérivée :
y = tan(x)
y = sin(x)/cos(x)
y'= ( sin(x)/cos(x) )'
y'= cos(x)cos(x) - (-sin(x))sin(x)
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cos(x)**2
y'= cos(x)**2 + sin(x)**2
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cos(x)**2
y'= 1
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cos(x)**2
y'= sec(x)**2