If the frequency of a given wave increases, what happens to the wavelength?

It shortens so that the tips reach faster

The product of frequency and wavelength is always the
same number . . . the wave's speed.

So if the frequency increases, the wavelength must decrease,
in order for their product not to change.

The boat's velocity relative to the riverbank can be resolved into two components. the component going north is 2.7 m/s and the component going west is 1.2 m/s.we add these two vectors and then find the magnitude of the resultant to get the speed.the magnitude of the resultant vector from adding can be obtained by the pythagorean theorem.    to two significant figures, the boat's speed relative to the riverbank is 3.0 m/s.