Students have described being focused like... / ... An eagle watching its prey ... a footballer with their eye on the ball ... ‘on it like a car bonnet’ ... catching a wave ... ‘just do it’ ... rolling your sleeves up ... keeping the rhythm in a band ... in the zone ... in a bubble ...a tiger

The eigenvalues 𝜆 of a square transformation matrix M may be found by solving det (M-𝜆I)=0.

God ſometimes ſent a light of fire, and pillar of a cloud, and the brightneſſe of an Angel, and the luſtre of a ſtar, and the ſacrament of a rainbovve to guide his people thorovv their portion of ſorrovvs, and to lead them through troubles to reſt: […]

Well, with fewer people doing two or three times the work, you may have already twigged to this.