Which of the following properties of integrals is true?
∫abf(x)dx=−∫baf(x)dx\int_a^b f(x) dx = -\int_b^a f(x) dx∫abf(x)dx=−∫baf(x)dx
∫ab[f(x)+g(x)]dx=∫abf(x)dx+∫abg(x)dx\int_a^b [f(x) + g(x)] dx = \int_a^b f(x) dx + \int_a^b g(x) dx∫ab[f(x)+g(x)]dx=∫abf(x)dx+∫abg(x)dx
∫abkf(x)dx=k∫abf(x)dx\int_a^b k f(x) dx = k \int_a^b f(x) dx∫abkf(x)dx=k∫abf(x)dx
∫aaf(x)dx=1\int_a^a f(x) dx = 1∫aaf(x)dx=1