2 / | | ___________ | / 2 | \/ 16 - 5*x dx | / -2
Integral(sqrt(16 - 5*x^2), (x, -2, 2))
TrigSubstitutionRule(theta=_theta, func=4*sqrt(5)*sin(_theta)/5, rewritten=16*sqrt(5)*cos(_theta)**2/5, substep=ConstantTimesRule(constant=16*sqrt(5)/5, other=cos(_theta)**2, substep=RewriteRule(rewritten=cos(2*_theta)/2 + 1/2, substep=AddRule(substeps=[ConstantTimesRule(constant=1/2, other=cos(2*_theta), substep=URule(u_var=_u, u_func=2*_theta, constant=1/2, substep=ConstantTimesRule(constant=1/2, other=cos(_u), substep=TrigRule(func='cos', arg=_u, context=cos(_u), symbol=_u), context=cos(_u), symbol=_u), context=cos(2*_theta), symbol=_theta), context=cos(2*_theta)/2, symbol=_theta), ConstantRule(constant=1/2, context=1/2, symbol=_theta)], context=cos(2*_theta)/2 + 1/2, symbol=_theta), context=cos(_theta)**2, symbol=_theta), context=16*sqrt(5)*cos(_theta)**2/5, symbol=_theta), restriction=(x > -4*sqrt(5)/5) & (x < 4*sqrt(5)/5), context=sqrt(16 - 5*x**2), symbol=x)
Now simplify:
Add the constant of integration:
The answer is:
/ // / / ___\ \ \
| || | |x*\/ 5 | ___________| |
| ___________ || |asin|-------| ___ / 2 | |
| / 2 || ___ | \ 4 / x*\/ 5 *\/ 16 - 5*x | |
| \/ 16 - 5*x dx = C + |<16*\/ 5 *|------------- + ----------------------| / ___ ___\|
| || \ 2 32 / | -4*\/ 5 4*\/ 5 ||
/ ||------------------------------------------------- for And|x > --------, x < -------||
|| 5 \ 5 5 /|
\\ /
/ ___\
___ |\/ 5 |
16*\/ 5 *asin|-----|
\ 2 /
4*I + --------------------
5
=
/ ___\
___ |\/ 5 |
16*\/ 5 *asin|-----|
\ 2 /
4*I + --------------------
5
4*i + 16*sqrt(5)*asin(sqrt(5)/2)/5
(11.2396463436482 + 0.557937300164848j)
(11.2396463436482 + 0.557937300164848j)
Use the examples entering the upper and lower limits of integration.